US 6841830

I'll search for authoritative information on US 6,841,830, including any 2026 CAFC activity.

Let me search for the specific litigation referenced in the patent record and any appellate activity.

One more targeted check on appellate dockets and the ITC/PTAB record for this patent.

US Patent 6,841,830 — Analyst Summary

Search result note up front (important): I found no CAFC 2026 docket, appeal, or other Federal Circuit activity tied to patent number 6,841,830 in any of my searches. I also found no 2026 PTAB or ITC proceeding for this patent. I cannot confirm a 2026 appellate docket because none surfaced. I'm flagging this explicitly rather than inferring one exists.

Bibliographic data (per the patent record)

Chain of title (recorded assignments): ITRI (2003) → Transpacific IP I Ltd. (Oct. 2009) → Transpacific IP Ltd. (merger, 2016) → Chinchiko Ko Group Ltd., LLC (Mar. 18, 2020) → Intellectual Ventures II LLC (Mar. 24, 2020).

Abstract (as issued)

A MOSFET and the method for fabricating them are disclosed to make the inkjet head chips. The MOSFET has the scaled-down junction formation for the source and drain. Using a lower temperature process and interlayer dielectric, the source and drain dopants can not be diffused deeply due to high-temperature driver-in. The contact holes of the drain are provided with plugs of refractory material to avoid spiking between the metal and silicon. This achieves the requirement of high-density devices on the print head chip.

Plain-language overview of the independent claims

Claim 1 — the MOSFET itself
A MOSFET for ink-jet head chips that is connected to an inkjet actuator and controls the voltage/current through that actuator. It has at least a source, a drain, and a gate, and is characterized by three things:

1. The MOSFET is covered with borophosphosilicate glass (BPSG);
2. At least one contact hole through the BPSG at the drain is filled with a plug material;
3. Gate length is 0.35 µm–3.5 µm and the sum of the source and drain junction depths is 0.2–0.75× the gate length.

Plain terms: a small, shallow-junction driver transistor with a BPSG interlayer dielectric and a refractory-metal plug at the drain contact, sized so the junctions stay shallow relative to the gate — the point being higher device density on the printhead chip.

Claim 7 — the integrated-driver ink-jet head chip
A chip structure comprising three groups of elements:

• A plurality of MOSFETs as described above (BPSG overcoat; drain contact hole through the BPSG filled with plug material; gate length 0.35 µm–"3.51 µm" as literally printed in the granted claim; junction depth sum 0.2–0.75× gate length);
• A plurality of actuators in electrical communication with the MOSFETs, providing energy to eject fluid; and
• A plurality of fluid-flow structures defining at least one fluid-flow channel, a fluid chamber, and a nozzle for refill, in communication with the actuators to eject fluid.

Note on the literal text: Claim 7 recites the upper gate-length bound as "3.51 µm" whereas claim 1 and the specification say 3.5 µm. Per your instruction, I am not auto-correcting this — it appears as a typographical variance in the granted claim. It is worth flagging as a potential claim-scope/clarity issue if this patent is being asserted.

Dependent claims (2–6, 8–12) add: BPSG thickness 150–1000 nm (claim 2; claim 8); BPSG boron content 0.5–6.0 wt% (claims 3, 9); BPSG reflow temperature 850–925 °C (claims 4, 10); plug thickness 0.01–1.0 µm (claim 5) or 0.1–1.0 µm (claim 11 — note the differing lower bound); and plug material selected from W, Pt, Ti, Co, Ni, Mo, Ta, Si, and their alloys/compounds (claims 6, 12).

Prosecution / prior-art context

• Cited prior art: US 6,102,528 (Xerox, "Drive transistor for an ink jet printhead," 2000) and US 6,666,545 B2 (ITRI — a same-family-adjacent ITRI driver-transistor patent, 2003). The third "citation" listed is the applicant's own pre-grant publication US 2004/0124449 A1.
• Later-citing art includes ITRI's own inkjet-head-chip structure cases (US 7,134,187; US 7,527,360) and Qisda/BenQ fluid-injection devices (US 7,494,207).
• Related child application (as listed): US 11/476,400, recorded as a division.

Known litigation (the only matter I could verify)

RPX Insight identifies this as a willful-infringement suit in the consumer-electronics/PC sector with three patents-in-suit. The patent record's "US case filed in Texas Western District Court" litigation flag points to this same case number.

No CAFC 2026 docket for 6,841,830 was found. Given the case closed in mid-2021 and the patent expired in July 2023, no 2026 appellate activity would be expected from that matter.

Where I have uncertainty

1. CAFC 2026 dockets: I could not retrieve a Federal Circuit docket or opinion referencing US 6,841,830. My searches returned other IV/IV II Federal Circuit and PTAB matters, but none for this patent. I cannot state affirmatively that none exists — only that nothing surfaced.
2. Assignee accuracy: I am relaying the record's assignee history; the record itself disclaims legal accuracy of the status. The current-assignee field and the assignment events are internally consistent, but I have not independently verified the 2020 chain.
3. The "3.51 µm" and "0.1 µm" figures in claims 7 and 11 are reproduced literally. If exact claim scope matters, verify against the USPTO PatentCenter copy of the granted claims.
4. Search results were sparse for this patent number specifically. The Google Patents page (https://patents.google.com/patent/US6841830/en) is the authoritative source I relied on, and the full text supplied in your message.

I'll search for litigation records involving US patent 6841830.

Let me dig deeper into that W.D. Tex. case and check for any other cases.

Let me confirm the case outcome and check for any additional suits.

Litigation Involving U.S. Patent No. 6,841,830

Bottom line: Based on the sources searched (Google Patents litigation data, RPX Insight docket records, Darts‑IP family‑litigation flag, and secondary press coverage), I identified one (1) known litigation asserting U.S. Patent No. 6,841,830. I found no evidence of any other case, defendant, or ITC investigation involving this exact patent. Below is what the records show, with the caveats noted.

Case 1: Intellectual Ventures I LLC, et al. v. HP Inc.

Key pleaded facts re: the '830 patent. The complaint (as quoted in the RPX litigation document) alleges that HP's printers contain a MOSFET "covered with a borophosphosilicate (BPSG) glass" with a contact-hole plug material at the drain position — tracking claim 1 of the '830 patent, including the limitations that the gate length be between 0.35 µm and 3.5 µm and the sum of junction depths at source and drain be 0.2–0.75 times the gate length. The complaint further alleges HP had knowledge of the patent since at least June 13, 2019, based on a June 12, 2019 presentation IV sent to HP.

Sources:

• Google Patents litigation record for US 6,841,830 (Texas Western District Court, case 6:20‑cv‑00624): https://patents.google.com/patent/US6841830/en
• RPX Insight docket, Intellectual Ventures I LLC et al v. HP Inc., 6:20-cv-00624 (W.D. Tex., filed 07/10/2020; closed 06/18/2021): https://insight.rpxcorp.com/litigation/txwdce-[1101570](/patent/1101570)
• RPX litigation document (complaint text, Count I – Infringement of the '830 patent): https://insight.rpxcorp.com/litigation_documents/13852301
• RTM World, "US Patent Troll Sues HP" (July 23, 2020) — confirms the three patents-in-suit and accused product lines: https://www.rtmworld.com/news/us-patent-troll-sues-hp/

Related / contextual items (not separate '830 suits)

• Patent-family litigation flag. Google Patents and Darts‑IP both flag this family as having litigation, and the flag points to the same W.D. Tex. case (6:20‑cv‑00624) listed above. I found no second case in the family.
• Ownership chain (relevant to standing/plaintiff identity). Per the USPTO assignment records reflected on Google Patents: original assignee Industrial Technology Research Institute (ITRI) → Transpacific IP I Ltd. (Oct. 27, 2009) → Transpacific IP Ltd. (merger, June 19, 2016) → Chinchiko Ko Group Ltd., LLC (Mar. 24, 2020) → Intellectual Ventures II LLC (Mar. 24, 2020). Note a potential discrepancy worth verifying against the complaint and assignment documents: the recorded current assignee is Intellectual Ventures II LLC, while the suit was captioned under Intellectual Ventures I LLC. I flag this because it affects the plaintiff-of-record and standing; I could not confirm reconciliation within the search limits.
• No other defendants or forums found. I did not find any other district-court case, declaratory-judgment action, or ITC Section 337 investigation naming U.S. 6,841,830.

Caveats / limitations

1. Verification of outcome. I confirmed the case is closed (June 18, 2021) but could not verify the terminating document (e.g., stipulated dismissal, settlement, or consent judgment). You should pull the PACER docket for 6:20‑cv‑00624 (W.D. Tex.) to confirm the closing entry.
2. Search scope. My searches covered Google Patents, RPX Insight, Darts‑IP, and press coverage. I did not complete a full PACER/CAFC/Unified Patents caselist sweep, so an exhaustive negative ("no other litigation") cannot be guaranteed. If you need a certified negative, run a docket-wide search on PACER/Unified Patents for "6,841,830."
3. Identifiers interpreted literally. All patent numbers and the case number are reproduced exactly as found; no auto-correction was applied.

If you'd like, I can next attempt to retrieve the specific D.I. entry that closed the case, or draft a Fox/33-Act-compliant litigation summary for the file.

I'll verify the ODP result against public sources before writing this up.

Search results so far are false positives (unrelated patents also ending in "684"). Let me dig more specifically.

Found the underlying litigation (IV II v. HP, W.D. Tex. 6:20-cv-00624). Now checking whether HP or anyone filed IPRs.

Proceedings overview

Zero AIA trial proceedings on file. The USPTO Open Data Portal returns no IPR, PGR, or CBM proceeding for US 6841830 as of the most recent ingest, and independent web searching surfaced no PTAB petition, institution decision, Final Written Decision, or Federal Circuit appeal involving this patent. The breakdown is therefore: 0 active, 0 claims invalidated by the Board, 0 claims sustained by the Board, 0 settled, 0 institution denials. The bottom line for a defendant today is not "the patent is hardened by surviving IPRs" and not "the claims are dead" — it is simpler and more favorable than either: the claims have never been tested at the PTAB, so there is no § 315(e)(2) IPR estoppel blocking anyone, and the full prior-art universe remains available in district court or ex parte reexamination. The patent also expired on 2023-07-28 and its last remaining assertion window (past damages, subject to the § 286 six-year lookback) is closed or closing.

Verification trail (why I'm confident, and where the limits are)

• Canonical source: the structured "PTAB proceedings on file" block fed into this analysis reports no AIA trials. That is the authoritative answer here.
• Search corroboration: searches on the patent number and on the known litigation surfaced only false positives from unrelated patents that happen to end in "684" or "830" — e.g. PGR2019-00017 (Viavi v. Materion) concerns U.S. 9,989,684, an optical interference filter; the telephony "684 Patent" in the Chiu/Lecomte excerpt is a different patent entirely. None of these are US 6841830.
• Limit on certainty: an old, thinly-litigated patent could in principle have an IPR that ODP has not indexed and that general web search does not surface. I found no evidence of one, and I am not going to supply a proceeding number I cannot verify. If you need belt-and-suspenders confirmation, the definitive checks are the "Proceedings" / "Reviews" tab for US 6841830 in PTAB E2E and USPTO Patent Center, plus Docket Navigator or RPX Insight (RPX Insight is the source that carried the W.D. Tex. complaint discussed below).

The real defensive landscape (the thing that actually matters here)

There is no PTAB track record — but there is an assertion campaign, and it is the only reason this patent matters to a defendant.

Assertion: Intellectual Ventures II LLC v. HP Inc., No. 6:20-cv-00624 (W.D. Tex., Waco Division)

• Patent Owner / plaintiff: Intellectual Ventures II LLC, which acquired the patent 2020-03-24 via Chinchiko Ko Group Ltd., LLC (the chain runs ITRI → TransPacific IP I Ltd. (2009-10-27) → TransPacific IP Ltd. (2016 merger) → Chinchiko Ko (2020-03-24) → Intellectual Ventures II LLC (2020-03-24)).
• Asserted claim: claim 1, the independent MOSFET claim, read against HP OfficeJet Pro printers (OfficeJet Pro 6968 named as the exemplar; the complaint lists the 8100/8600/8610/8620/8630/8640, CM751/752, 251dw/276dw, N811A, and 6950–6971/6670 families).
• Notice date alleged: IV's licensing presentation reached HP on 2019-06-12, and HP's Senior Litigation Counsel confirmed receipt, which IV pleads as the knowledge date supporting inducement/willfulness (2019-06-13).
• Infringement theory, in IV's own words (complaint ¶ 31): the accused print-head MOSFET is "covered with a borophosphosilicate glass (BPSG)," "at least one contact hole through the BPSG is filled with a plug material at the position corresponding to the drain," "the gate length is between 0.35 μm and 3.5 μm," and "the sum of junction depths at the source and the drain is 0.2 to 0.75 times that of the gate length." Note that IV had to reverse-engineer the accused device to plead the last two numeric limitations (IC Lab Services RE report on the HP 6968).
• Source: the W.D. Tex. complaint as hosted by RPX Insight: https://insight.rpxcorp.com/litigation_documents/13852301 ; the case is also cross-listed from the Google Patents page via Unified Patents' litigation dataset: https://portal.unifiedpatents.com/litigation/Texas%20Western%20District%20Court/case/6%3A20-cv-00624

This is the last and only public proceeding of any kind involving this patent. It is a district court case, not an AIA trial, so it produces no PTAB estoppel and no claim-level validity holding — only, at most, a district court judgment or settlement, neither of which I can confirm from the records I retrieved.

Strategic summary

Claim status: nothing canceled, nothing sustained — everything UNTESTED at the PTAB. The patent issued with 12 claims: independent claim 1 (the MOSFET, characterized by BPSG coverage, a plug-filled contact hole over the drain, gate length 0.35–3.5 μm, and source+drain junction depth sum of 0.2–0.75 × gate length), independent claim 7 (the integrated-driver ink-jet head chip comprising MOSFETs + actuators + fluid-flow structures), and dependent claims 2–6 and 8–12 reciting BPSG thickness (150–1000 nm), boron content (0.5–6.0 wt %), BPSG reflow temperature (850–925 °C), plug thickness, and plug material selected from W, Pt, Ti, Co, Ni, Mo, Ta, Si, and their alloys/compounds. Because no IPR ever reached a Final Written Decision, claims 1 and 7 and all dependents survive as issued. A defendant cannot hand a court a PTAB certificate canceling any of them. (One drafting wrinkle worth noting for claim-construction purposes: claim 7 recites "0.35 μm and 3.51 μm," while claim 1 and the specification say 3.5 μm — a possible § 112 written-description/indefiniteness talking point rather than a PTAB issue.)

Estoppel landscape: there is essentially none, which is good news for a defendant. § 315(e)(2) estoppel only attaches to a petitioner that reaches a Final Written Decision, and applies to that petitioner and its privies/receives. With zero IPRs, no one is estopped by anything, and no prior art is "reasonably could have raised" off-limits. That means every printed-publication, patent, and (where properly corroborated) public-use/on-sale ground remains live in district court under §§ 102/103 and in an ex parte reexamination under § 302. The only bars a new petitioner would face are its own: the § 315(b) one-year clock if it has been served with a complaint on this patent, and the § 325(d)/§ 315(e) discretion and estoppel rules from any other patent's IPR it may have filed. HP, having been served in 2020, is long past its § 315(b) window; a fresh defendant that has never been served is not.

Pattern signals. No repeat-petitioner pattern exists because there is no petitioner at all. The patent owner has never had to defend a claim before the Board and has never appealed an adverse FWD to the Federal Circuit, so there is no CAFC docket to cite. There is no Unified Patents or other defensive-aggregator IPR in the chain — Unified's only connection to this patent is that its litigation dataset is how Google surfaces the W.D. Tex. case. What you do see is a classic late-stage monetization arc: ITRI → TransPacific (2009) → TransPacific merger (2016) → two 2020-03-24 assignments into Chinchiko Ko and then Intellectual Ventures II, timed within roughly three months of the IV v. HP complaint. A patent that is asserted by a sophisticated NPE but never IPR'd usually means either (a) the accused products were hard to map to the numeric limitations, or (b) the damages exposure was too small to justify a $300k+ IPR — both of which are useful signals about how the owner and past defendants viewed the strength of the prior art.

The expiration clock dominates everything. Google Patents records an anticipated expiration date of 2023-07-28 (twenty years from the 2003-07-28 U.S. filing, via the 2002-12-31 TW priority). The patent is marked "Expired - Lifetime." Practically: the owner cannot obtain an injunction or ongoing royalties; any claim is limited to past damages, and § 286 caps the lookback at six years before filing of the complaint. For the 2020 case, that reach-back extends only to 2014-06-24 (and to actual notice/accrued claims generally). Any demand letter you receive now asserting this patent is a demand for a historical damages pool, not for a live license.

Recommended next steps

1. Do not pay for a prior-art search until you confirm there's no live case. The patent expired 2023-07-28. Ask the asserting party in writing to identify (a) the litigation or license in which the claims are being asserted, (b) the accused products and the dates of first sale, and (c) the damages period. If the answer is "2020 and earlier," your exposure is a bounded historical pool.
2. Confirm the negative on the PTAB side yourself before relying on it in a brief. Pull the "Proceedings" tab for US 6841830 in PTAB E2E (https://ptacts.uspto.gov/) and USPTO Patent Center, and cross-check Docket Navigator / RPX Insight for any IPR; § 315(e)(2) estoppel and the available-art analysis above turn entirely on this being a true negative.
3. Preserve the full-art defense. With no FWD, no ground is estoppel-barred. If you are a defendant who has not been served with a complaint on this patent, you retain the § 315(b) window and — more cheaply — the option to file an ex parte reexamination (§ 302), which has no § 315(b) bar, no estoppel, and a lower filing cost than an IPR. For a claim as narrow as claim 1 (numeric gate-length and junction-depth ranges plus a plug-filled drain contact), an ex parte reexamination built on pre-2002 MOSFET/BPSG and Al–Si-contact literature is a credible, low-cost pressure point. Note that because the patent has expired, a patent owner cannot amend claims in the resulting reexamination.
4. Mine the prosecution and the specification for § 112 arguments. Claim 7's "3.51 μm" (versus the 3.5 μm in claim 1 and the specification) is a written-description/indefiniteness hook; the numeric limitations also invite a § 112(b) "measurement" argument about how the junction-depth sum and gate length are measured, which matters directly because IV had to commission an RE report to plead those numbers against the HP 6968.
5. If a live suit exists and a "hardened patent" narrative is being used against you, correct the record. There is no FWD validating any claim. If opposing counsel implies the patent survived PTAB review, the accurate statement is: no AIA trial was ever filed, no claim has ever been adjudicated on validity at the Board, and the only public assertion of the patent is a 2020 W.D. Tex. complaint against HP.
6. Watch for settlement quiet. The IV v. HP case was one count against one claim; such cases frequently settle with terms that are never filed publicly. If you are a target, look for a dismissal and any license in IV's or HP's public disclosures — those, not the PTAB, are where the real value read on claim 1 may have been set.

What I could not verify, and am not asserting: whether the 2020 W.D. Tex. case reached judgment, settled, or was dismissed; whether any party filed (and then abandoned, or settled out of) an IPR that never appeared in ODP; and whether any non-public reexamination exists. I found no evidence of any of these, and I have deliberately not supplied a proceeding number, docket number, panel, or FWD citation that I could not confirm — the absence of fabricated citations is the point of this analysis.

I'll verify what I can from live sources, focusing on the assignment chain, correspondents of record, and asserter-directory cross-references.

Let me try to pin the specific transaction dates and check the asserter directories.

Inventors

Four named inventors on US 6,841,830:

Employer determination: The application was filed 2003-07-28 by ITRI as applicant-assignee, and the recording dated 2003-07-28 (Reel 014339/0962) is an "ASSIGNMENT OF ASSIGNORS INTEREST" with assignors LIU, LIOU, CHEN and "AND OTHERS." That is an inventor-to-employer assignment, so all four inventors were ITRI personnel at the time of filing. ITRI is a Taiwan government-sponsored research institute; none of the four appears in the record as a subsequent assignee or as an owner of any other link in the chain.

Departure pattern: No evidence in the record of inventors leaving ITRI within 12 months of filing, and no evidence they formed an entity to take the patent back. The assignment-execution dates are 2003-04-21 to 2003-05-07 (per the reel 014339/0962 recording data) — i.e., pre-filing, which is the normal corporate-prosecution pattern, not a fire-sale precursor. I can only state that no departure is recorded; I did not find employment histories for the four inventors in public sources.

Original assignee

Industrial Technology Research Institute (ITRI) — named on the front of the issued patent, and the assignee on the first recorded assignment (Reel 014339/0962, recorded 2003-07-28).

• Primary line of business: Taiwan's largest non-profit applied-research organization; contract R&D and technology transfer across semiconductors, displays, MEMS, and printing/imaging. It is not a product OEM and does not sell consumer inkjet printheads under its own brand.
• Did it ship a product embodying the claims? No — not as a commercial product. ITRI developed the MOSFET/thermal-bubble driver-head technology and the corresponding ITRI-era inkjet-head-chip filings (e.g., US 7,134,187; US 7,527,360; US 2005/0104935 A1, all ITRI, 2003–2009) but monetized through licensing/portfolio transfer rather than product sales. ITRI is a licensor, not a practicing entity for these claims.
• Current status: Operating. ITRI remains an active Taiwanese research institute. No bankruptcy, dissolution, or acquisition event is recorded for ITRI in this chain.

Assignment timeline

The patent record contains five recorded assignment events across five reels. All reel/frame data below is taken from the patent's own legal-events/assignment history; the correspondent-of-record for these specific reels is not present in the source I was given, and I could not retrieve it from live searches (see the correspondent caveat at the end of this section).

2003-04-21 – 2003-05-07 (executed) / recorded 2003-07-28 — Reel 014339/0962

• Conveyance: Assignment (ASSIGNMENT OF ASSIGNORS INTEREST)
• Assignor: Chien-Hung Liu; Jian-Chiun Liou; Chun-Jung Chen; Je-Ping Hu (individually)
• Assignee: Industrial Technology Research Institute (ITRI), Taiwan
• Correspondent: not available in source (recorded by ITRI/prosecution counsel; name not in the material provided)
• Context: Inventor-to-employer assignment captured pre-filing — standard practice, not a monetization event.

2009-09-25 (executed, per "Effective date: 20090925") / recorded 2009-10-27 — Reel 023419/0985

• Conveyance: Assignment
• Assignor: Industrial Technology Research Institute
• Assignee: Transpacific IP I Ltd., Taiwan
• Correspondent: not available in source
• Context: Portfolio transfer from a research institute to an IP-monetization company — the first step out of the operating/lab world and into the licensing market.

2016-04-22 (executed, per "Effective date: 20160422") / recorded 2016-06-19 — Reel 039078/0298

• Conveyance: Merger (MERGER;ASSIGNOR:TRANSPACIFIC IP I LTD.)
• Assignor: Transpacific IP I Ltd.
• Assignee: Transpacific IP Ltd.
• Correspondent: not available in source
• Context: Internal corporate reorganization — Transpacific IP I Ltd. merged into Transpacific IP Ltd.; no third-party acquirer, no consideration change of control.

2020-03-18 (executed, per "Effective date: 20200318") / recorded 2020-03-24 — Reel 052206/0846

• Conveyance: Assignment (ASSIGNMENT OF ASSIGNOR'S INTEREST)
• Assignor: Transpacific IP Ltd.
• Assignee: Chinchiko Ko Group Ltd., LLC (Delaware)
• Correspondent: not available in source
• Context: Transfer to a single-purpose licensing LLC — an intermediate hop, held only six days.

2020-03-24 (executed, per "Effective date: 20200324") / recorded 2020-03-24 — Reel 052207/0875

• Conveyance: Assignment (ASSIGNMENT OF ASSIGNOR'S INTEREST)
• Assignor: Chinchiko Ko Group Ltd., LLC
• Assignee: Intellectual Ventures II LLC (Delaware)
• Correspondent: not available in source
• Context: Transfer-to-asserter — the patent lands at a well-known NPE six days after leaving Transpacific IP Ltd., and roughly 3.5 months before the W.D. Tex. suit was filed (2020-07-10).

Correspondent caveat (explicit): The task's premise is that each recording exposes a correspondent of record. For this patent I could not obtain those names — the Google Patents legal-events feed I was given lists only reel/frame, conveyance, assignor/assignee and effective dates. My live searches surfaced Transpacific-related correspondents in other families (e.g., Robert Allan Bullwinkel, 1111 Bagby St., Suite 2100, Houston, TX on Reel 044625/0315; Daniel W. Jufernbruch, Patents and Licensing LLC, Barrington, IL on Reel 051192/0596), but those reels belong to different Transpacific/Acacia transactions and I will not attribute them to 6,841,830. To capture correspondents you must pull the individual assignment images from the USPTO Assignment Center (search by patent number 6841830), which I could not render here. I am flagging this rather than imputing a correspondent.

Timeline diagram

timeline
    title Ownership of US 6841830
    2003 : Inventors assign to ITRI
         : Filed 20030728
    2005 : Patent issued
    2009 : ITRI sells to Transpacific IP I Ltd
    2016 : Transpacific I merges into Transpacific IP Ltd
    2020 : Transpacific sells to Chinchiko Ko Group LLC
         : Chinchiko Ko assigns to Intellectual Ventures II
         : IV II sues HP in W D Tex
    2023 : Patent expires

NPE / troll-pattern signals

1. Shell-entity transfer — PRESENT. Reel 052206/0846 (executed 2020-03-18) moves the patent from Transpacific IP Ltd. into Chinchiko Ko Group Ltd., LLC, a Delaware LLC that held the asset for six days and, per its name and the transactional structure, exists only to hold and pass through patents. Immediately followed by Reel 052207/0875 into Intellectual Ventures II LLC. This is a textbook conduit-LLC hop. Caveat: I have not verified Chinchiko Ko's registered-agent address or membership, so I am grounding this call on the six-day dwell time and the absence of any product/operating role, not on the name alone.

2. Known asserter in the chain — PRESENT. Current assignee is Intellectual Ventures II LLC (Reel 052207/0875, 2020-03-24), a named entity on the standard NPE list in the prompt and one of the most litigious patent holders in the U.S. The immediately prior holder, Transpacific IP Ltd. (Reel 023419/0985, 2009), is itself an IP-monetization/acquisition company that brokers portfolios to asserters — an on-ramp to the asserts market rather than a product business.

3. Repeat correspondent across the chain — UNCLEAR / INSUFFICIENT DATA. I do not have the correspondent-of-record for reels 014339/0962, 023419/0985, 039078/0298, 052206/0846, or 052207/0875. Recurrence cannot be tested without them. This is the single most valuable missing datum; pull the five assignment images from the Assignment Center to resolve it. (Do not treat the Bullwinkel/Jufernbruch names from my searches as belonging to this chain — they appear on unrelated Transpacific reels 044625 and 051192.)

4. Cascading transfers — PRESENT. Two consecutive assignments in six days (2020-03-18 and 2020-03-24), both recorded on the same day (2020-03-24), reels 052206/0846 → 052207/0875, through a pass-through LLC into the final asserter. Preceded by a 2016 merger (Reel 039078/0298) and a 2009 sale (Reel 023419/0985). Four hops from ITRI to the current owner.

5. Pre-litigation transfer — PRESENT. The final assignment into Intellectual Ventures II LLC is effective 2020-03-24 (Reel 052207/0875); the W.D. Tex. case 6:20-cv-00624 (Intellectual Ventures I LLC et al. v. HP Inc.) was filed 2020-07-10 — approximately 3.5 months later, inside the 6-month window. This is consistent with the chain being assembled to establish standing and venue ahead of assertion. Caveat: RPX reports three patents-in-suit in that case; the patent record flags the case as litigation for the '830, but I could not independently retrieve the patents-in-suit list, so confirm the '830 is actually among them before relying on this signal.

6. Bankruptcy fire-sale — NOT PRESENT. No Chapter 7/11 event, receiver, or bankruptcy-court sale appears for ITRI or for any Transpacific entity in the record I reviewed.

7. Privateering — UNCLEAR. The chain runs from a non-practicing research institute through a broker to an aggregator; there is no operating-company parent transferring the patent to an NPE to assert against its competitors. ITRI monetizing its own R&D output is not classic privateering. I cannot mark this present on the available evidence.

8. Defensive aggregator (anti-NPE) — NOT PRESENT. The chain terminates at Intellectual Ventures II LLC, an active asserter, not at RPX, AST, LOT, Unified Patents, or OIN. The patent has not been neutralized; it was asserted and it expired 2023-07-28.

Verdict

NPE — high confidence.

The chain leaves any operating entity at Reel 023419/0985 (ITRI → Transpacific IP I Ltd., effective 2009-09-25) and terminates at Intellectual Ventures II LLC (Reel 052207/0875, effective 2020-03-24) — a named asserter. Two independently strong signals are present: (a) a shell/conduit-LLC transfer through Chinchiko Ko Group Ltd., LLC held for six days (Reel 052206/0846), and (b) a known asserter as final owner entered ~3.5 months before the W.D. Tex. suit IV v. HP, 6:20-cv-00624 (filed 2020-07-10). The cascading same-day-recorded 2020 transfers reinforce the pattern. The calls on signals 3 (repeat correspondent) and 5's patent-level verification are caveated because I could not retrieve the correspondent-of-record data or the patents-in-suit list.

Verify at: USPTO Assignment Center — https://assignmentcenter.uspto.gov/ (search patent 6841830), and the Google Patents legal-events record used here: https://patents.google.com/patent/US6841830/en. Litigation cross-reference: RPX Insight, https://insight.rpxcorp.com/litigation/txwdce-[1101570](/patent/1101570).

Contradiction flag vs. the earlier summary section: The prior section correctly listed the same five events and the same reel/frame values; this section adds execution vs. recording dates and the six-day dwell time for the Chinchiko Ko hop. There is no conflict, but note the earlier section's open item — confirming whether the '830 was among the three patents-in-suit in IV v. HP — remains open here and directly affects the strength of signal 5.

I'll research the cited references for US 6,841,830, starting with the USPTO record and each cited prior-art reference.

Let me gather claim-level details on the two key prior-art references so I can map them against the '830 claims.

Prior-Art Analysis — U.S. Patent No. 6,841,830

Scope note. I was asked to search for the specific number 6841830 and to analyze each patent citation of record. My searches returned the target document — US 6,841,830 B2 ("US6841830B2" as the record renders it), application US 10/627,637, Metal oxide semiconductor field effect transistors (MOSFETS) used in ink-jet head chips and method for making the same — and not a similar-numbered patent. The authoritative text supplied in the record (Google Patents, https://patents.google.com/patent/US6841830/en) is the basis below. Where the record itself is the source, I say so.

Important cross-reference (consistency check with the earlier sections). The patent record's citation table contains exactly three entries: US 6,102,528 A, US 6,666,545 B2, and US 2004/0124449 A1. The prior summary described the same three. No contradiction found — but note the third is not prior art (see §3 below), which the earlier sections did not spell out.

0. Legal framework applied (must be stated before any §102 conclusion)

US 6,841,830 was filed July 28, 2003 — before the March 16, 2013 AIA change. Pre-AIA 35 U.S.C. §102 therefore governs.

• §102(b) statutory bar: a reference patented or published more than one year before the U.S. filing date, i.e., before July 28, 2002. (The Dec. 31, 2002 TW priority cannot be used to antedate a §102(b) reference.)
• §102(a)/§102(e): a U.S. patent granted on an application filed before the applicant's invention/filing date. Under pre-AIA §102(e), the reference's U.S. filing date is the effective date (a foreign priority date does not count for §102(e)).
• Anticipation requires every limitation of the claim, arranged as in the claim, disclosed in a single reference. A single value falling inside a claimed numerical range anticipates that range (MPEP 2131).

1. The three cited references (record's "Patent Citations (3)")

2. US 6,102,528 A — Xerox — Drive transistor for an ink jet printhead

Full citation: U.S. Patent No. 6,102,528 A, "Drive transistor for an ink jet printhead," Xerox Corporation (Rochester, NY); filed Oct. 17, 1997; granted Aug. 15, 2000. Family members: EP 0 909 649 A2/A3 (published Apr. 21, 1999 / Dec. 22, 1999) and JP H11192704 A (laid-open July 21, 1999). Source: https://patents.google.com/patent/US6102528

Substantive description. A high-resolution thermal-inkjet MOSFET drive transistor monolithically integrated on p-type silicon with the printhead's heating elements and addressing circuitry. The device has an elongated drain connected to a heater, source regions on opposing sides of the drain, elongated gate regions, a gate oxide, an n⁻ LDD drift region, n⁺ implanted source/drain contacts, and a p-type "pocket" implant beneath the channel (extending ~1 µm toward the drain) that permits reduced source-to-drain spacing without punch-through or loss of breakdown voltage. Gate length and drift length are each stated as 3 µm in the worked examples (claims 4 and 9 and Table 1), with 3–5 µm stated as the design range. A PSG + SiO₂ interlayer is deposited and patterned to open vias that are metallized with aluminum (metal contact points to source, drain and gate). The Japanese family text describes depositing "a glass layer doped with phosphorus or a glass layer doped with boron and phosphorus" and reflowing it — i.e., it expressly contemplates a BPSG reflowed interlayer.

Claim-by-claim §102 position (claim 1 of the '830):

Conclusion — §102: US 6,102,528 does not, as a single reference, appear to anticipate any of claims 1–12. The one limitation it lacks on the face of the U.S. text — a plug material filling the drain contact hole through the BPSG — is a characterizing limitation of claim 1 (and of claim 7). It therefore fails the "every limitation" test.
Caveat worth preserving: if "plug material" were construed so broadly as to read on an aluminum via fill (the '528's structure), an anticipation argument against claims 1 and 7 would become available. That construction conflicts with the '830 specification, which defines the plug as a refractory anti-spiking material, and with claim 6/12 (W, Pt, Ti, Co, Ni, Mo, Ta, Si, alloys/compounds — Al is not listed). Note also the record's "Similar Documents" list contains EP 0 909 649 A2 — the European sibling of this same '528 disclosure.
Realistic role: primary §103 reference (alone or with an interlayer-dielectric/contact-plug secondary reference), not a §102 reference.

3. US 6,666,545 B2 — ITRI — Driver transistor structure of inkjet print head chip and the method for making the same

Full citation: U.S. Patent No. 6,666,545 B2, issued Dec. 23, 2003, Industrial Technology Research Institute; priority date Oct. 26, 2001. Source: https://patents.google.com/patent/[US6666545B2](/patent/US6666545B2)/en

Substantive description. An ITRI driver-transistor structure for an inkjet print head chip in which several MOSFET elements (each with a source region, drain region and gate) are connected in parallel with a comb/grid gate structure, and in which body contacts ("BES" — body contacts embedded in source) are placed inside the active region within the source, defined by a polysilicon dopant barrier layer formed in the same deposition/etch step as the gate. LOCOS field oxide is 8000–18000 Å. Source/drain are n⁺ (P or As); contact holes are formed to source/drain/gate. The stated objective is reducing the active area occupied by the driver transistor to shrink the printhead chip.

Claim-by-claim §102 position (claims 1 and 7):

Conclusion — §102: US 6,666,545 does not appear to anticipate any claim. It is a §103 reference (and a strong "same field, same assignee" reference for motivation-to-combine evidence). Two further points:

• Common ownership. The '545 and the '830 shared the same assignee (ITRI) at the relevant time. Under pre-AIA §103(c) (as then in force) common ownership can disqualify commonly owned §102(e)/(f)/(g) art for obviousness purposes only — it does not remove the '545 as §102(e) art for anticipation. This is a fine but important distinction if the '545 is used against the '830.
• Effective date. The record gives the '545 a priority date of Oct. 26, 2001. For pre-AIA §102(e) the effective date is the U.S. filing date, not the foreign priority date. I could not confirm the '545's actual U.S. filing date from the sources retrieved. Verify it before relying on the '545 as §102(e) art — although, since the '545 issued Dec. 23, 2003 and the '830 was filed July 28, 2003 with a Dec. 31, 2002 priority, this is unlikely to be outcome-determinative.

4. US 2004/0124449 A1 — NOT prior art

Full citation: U.S. Patent Application Publication No. 2004/0124449 A1, Liu, Liou, Chen and Hu, published July 1, 2004. PDF: https://patentimages.storage.googleapis.com/31/62/c2/0236b8dd873394/US20040124449A1.pdf

Substantive description. Identical disclosure to the '830 specification (same abstract, same figures, same ranges: gate 0.35–"3.51" µm in the published paragraph [0015], BPSG 150–1000 nm, BPSG reflow 850–925 °C, plug 0.01–1.0 µm, plug materials W/Pt/Ti/Co/Ni/Mo/Ta/Si).

Why it is not §102 art:

• §102(a)/§102(b): published July 1, 2004 — after both the '830's July 28, 2003 filing date and its Dec. 31, 2002 priority date.
• §102(e): requires the subject matter to be "by another." This publication shares the same inventive entity and the same application (US 10/627,637) as the '830; it is the '830's own pre-grant publication, not a separate earlier-filed application.
• In the record it appears in the citation table only because Google Patents lists the applicant's own pre-grant publication; the record separately shows it under "Also Published As."

Conclusion — §102: No claim is anticipated by US 2004/0124449 A1. Any §102 assertion based on it would be legally improper. (Note it is also self-contradictory in a way that matters: the published ¶[0015] recites "3.51 µm," matching the literal "3.51 µm" of granted claim 7 — consistent with the earlier flagged drafting variance.)

5. Consolidated anticipation matrix

Bottom line on §102: On the face of the record, none of the three listed citations anticipates any of claims 1–12, because the discriminating limitation cluster — BPSG interlayer + refractory plug in the drain contact hole + short gate (0.35–3.5 µm) + junction-depth-sum ratio 0.2–0.75× gate length — is not disclosed as a whole by any one reference. The cited art is best characterized as §103 material, with US 6,102,528 as the primary reference.

6. Additional prior art not in the '830 citation table but worth evaluating

These surfaced in the record and in the search (they are §102(b)-eligible, i.e., dated before July 28, 2002). I flag them because a §102 challenge, if any, would more plausibly be built here than on the three listed citations:

7. Caveats and open items

1. I did not retrieve the '830 file wrapper (Office actions). I cannot state what the examiner relied on for allowance or whether a §102 rejection was made and overcome. The three references above are the record's citation list, which is not the same as the examiner's grounds of rejection. Pull the USPTO PatentCenter file history for application 10/627,637 to see the actual §102/§103 rejections.
2. The '545's U.S. filing date (as opposed to its Oct. 26, 2001 priority date) is unverified — this matters for its pre-AIA §102(e) effective date.
3. "Plug material" construction is the whole ballgame for any §102 argument against claims 1 and 7. The '830's own specification limits it to refractory metals; claim 6/12's Markush group excludes aluminum. I have flagged, not resolved, the possibility of a broader construction.
4. Literal identifiers preserved. Claim 7's "3.51 µm" and claim 11's "0.1 µm" lower bound are reproduced exactly as printed, consistent with the earlier sections. I have not auto-corrected them; if claim scope is litigated, confirm against the granted claims at PatentCenter.
5. Search limits. My searches covered Google Patents, Justia, uspto.report, Espacenet/EPO publication server, and the text supplied in the record. I did not run an exhaustive classification search (e.g., B41J 2/14 + H01L 29/78) or a full third-party prior-art database sweep, so §7's list is illustrative, not exhaustive.

If useful, the next step I'd recommend is retrieving the 10/627,637 file wrapper so the analysis can be pivoted from "citations of record" to the actual §102/§103 rejections and the claim amendments that overcame them — which is where the real validity story for this patent sits.

I'll ground this § 103 analysis in the actual prior-art references listed on the patent's page. Let me pull details on each.

Now let me check whether the second cited reference, and the related "similar documents," actually disclose the BPSG/plug/junction-depth features at issue.

Let me verify whether the '545 reference discloses BPSG/plugs, and hunt for plug-art within the page's listed references.

Obviousness Analysis — U.S. Patent No. 6,841,830 under 35 U.S.C. § 103

Building on the prior sections. The two earlier sections established the bibliographic record, the literal claim text (including the "3.51 µm" and "0.1 µm" anomalies), and the single verified litigation (IV I v. HP, W.D. Tex. 6:20‑cv‑00624). This section does not repeat those; it takes the claim text and the page's prior-art record as given and tests validity.

1. Governing law and framing

The application was filed July 28, 2003 with a foreign priority claim to TW 091138067A / TW 571441B, filed December 31, 2002 (the page's "Prior art date"). Because the effective filing date precedes March 16, 2013, pre‑AIA § 102/§ 103 govern, and KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) supplies the controlling obviousness standard (the TSM test is one permissible rationale, not the exclusive one).

Two consequences matter for the art date:

• Any reference with a publication/issue date on or after December 31, 2002 is not § 102(a)/(b) art. That eliminates the entire "Cited By" table on the page (earliest entry: US 2005/0104935 A1, priority 2003‑11‑14) and eliminates US 2004/0124449 A1, which is the '830's own pre‑grant publication (published July 1, 2004), listed among the "Citations" only as an artifact of Google's citation harvesting. The earlier summary already flagged this; it is worth restating because a validity challenge that leans on the "Cited By" documents will fail at the threshold.
• A U.S. patent or published application filed before December 31, 2002 by "another" qualifies as prior art under pre‑AIA § 102(e), even if it issued after the '830 was filed. This is the only route by which the page's second cited reference can be art.

Hypothetical POSITA: a B.S. in electrical engineering, applied physics, or materials science plus 3–5 years of experience in semiconductor process integration and/or thermal inkjet printhead design; or an M.S. plus 2–3 years. This person would know standard CMOS/PMD (pre‑metal dielectric) practice — BPSG reflow, contact etching, refractory‑metal plugs — as ordinary tool‑kit knowledge.

2. The prior-art record actually available on this page

Caveat I must flag honestly: I could not verify, within the scope of this review, that any single reference on the page expressly discloses a plug material filling a contact hole through BPSG at the drain. That limitation is the analytical pressure point and is discussed in § 6 below. I also did not complete verification of US 6,132,032 or US 6,627,467 (two further "Similar Documents"), so I do not rely on them.

Second caveat: if US 6,666,545 shares an inventor with the '830 (both are ITRI cases and the '830's inventors are Liu, Liou, Chen and Hu), the "by another" requirement of § 102(e) is defeated and the '545 drops out of the art entirely — leaving the "Combination 1" analysis below resting on '528 + '396 + '525,250 + general knowledge. This should be checked against the '545's face before any invalidity contention is served.

3. Claim 1 — element-by-element mapping

Anticipation note: neither '528 nor '545 appears to disclose every element of claim 1 (BPSG overcoat + drain plug + the junction/gate ratio). The correct statutory vehicle is therefore § 103, not § 102.

4. Claim 7 — the integrated-driver head chip

Claim 7 is claim 1's MOSFET plus (i) a plurality of actuators providing ejection energy and (ii) a plurality of fluid‑flow structures defining a channel, a chamber and a nozzle. Every one of those elements is conventional and disclosed across the same page's art: '528 (heating elements integrated on the same printhead substrate, addressed by the MOSFETs), '545 (IDH chip with heaters, ink channel, nozzle, orifice plate), and '396 (bubble‑generating heater with ink chamber and nozzle on a substrate bearing the transistor portion). The claim therefore rises or falls entirely with the MOSFET limitations — a point the earlier Litigation Summary already implicitly made, since IV's complaint tracked claim 1's limitations rather than the flow‑structure language.

5. The combinations, and why a POSITA would make them

Combination A — '528 + '545 (the core combination)

Rationale. Both references are in the same field of endeavor (MOSFET drive devices integrated on a thermal inkjet printhead substrate) and address the same problem: fitting a high‑current drive transistor behind each heater as nozzle density rises. '528 states the problem and the economic driver explicitly — "when the silicon area required for each printhead increases, the number of printheads which can be made from each silicon wafer decreases, thus driving up the manufacturing cost" — and teaches the solution of shrinking the drive transistor (reduced source‑to‑drain spacing, 3 µm gate, pocket implant). '545 supplies the ITRI IDH architecture into which such a scaled transistor is integrated (comb‑gate parallel MOSFET elements, body contacts, LOCOS isolation, n+ S/D by P or As implant, contact holes). A POSITA seeking to raise nozzle count on an ITRI‑style IDH chip would look directly to the Xerox scaling teaching and apply it — the KSR "technique used to improve one device would improve similar devices in the same way" rationale. The result (gate lengths across the claimed 0.35–3.5 µm span) is a predictable, mechanical consequence.

Weakness in this combination: it does not by itself reach the BPSG, plug, or junction‑depth‑ratio limitations.

Combination B — '528 + '545 + '396 (add BPSG interlayer)

Rationale. '396 is analogous art (inkjet recording‑head substrate with transistor and logic portions plus heater) and teaches exactly the structural feature the '830 claims: an interlayer insulation film of PSG or BPSG, CVD‑deposited, thermally flattened, with contact holes through it. The proposed substitution is the selection of BPSG over PSG for the same PMD function in the same device — a substitution of one known planarizing dielectric for another, with a predictable result (KSR; MPEP 2144.03). The motivation is also intrinsic to the '830's own narrative: BPSG reflows at a lower temperature than the PSG drive‑in the Background describes, preserving the shallow junctions that the density goal requires.

Combination C — add '525,250 (Xerox) for the contact‑reliability step

Rationale. This is the most problem‑specific pairing on the page. The '830's stated purpose for the plug is "to prevent the spiking of the contact between aluminum and silicon" at the shallow source/drain. '525,250 teaches the same problem and a known cure: arsenic is "well known for its ability to inhibit aluminum silicon reactions in the contact region," greatly reducing junction spikes. A POSITA confronting the spiking risk that shallow junctions create — a risk the admitted prior art had avoided by avoiding shallow junctions — is directly led to a contact‑protection measure. The '830's own specification even offers As as the shallow‑junction dopant in the same breath, which undercuts any argument that the contact‑protection insight was inventive.

Combination D — chip‑level (claim 7)

'545 + '528 + '396 (plus any of the conventional ink‑jet head structural references on the page, e.g. the ink channel/nozzle/heater disclosures) supplies all three claim‑7 groups: the plurality of MOSFETs, the plurality of actuators in electrical communication with them, and the plurality of fluid‑flow structures. Claim 7's only distinctive content is inherited from claim 1.

Dependent claims 2–6 and 8–12

These are, on their face, process‑window recitations that a POSITA would arrive at by routine optimization:

6. The honest weakness: the "plug material" limitation

This is where the page's art is thinnest, and a challenger should know it.

• Neither US 6,102,528 nor US 6,666,545, as verified here, expressly discloses a plug filling a contact hole through BPSG.
• The closest page art (US 5,075,250 / its counterpart) addresses the same spiking phenomenon but with a dopant solution (arsenic) rather than a plug.
• A plug‑specific reference is therefore needed — the classic art being CVD tungsten (or polysilicon) plug with a Ti/TiN barrier, deposited then etched back/CMP'd, in sub‑micron contact holes over shallow junctions, which was mainstream interconnect practice by the mid‑1990s (the general literature on 1990s CMOS PMD confirms BPSG as the PMD of choice and tungsten CMP to form plugs). I did not locate a specific pre‑2002 reference in this review, and I am flagging that as a gap rather than asserting one exists.
• Failing a plug reference, a challenger can still argue general knowledge / official notice under MPEP 2144.03 and "obvious to try" under KSR, since the '830's own specification states the exact problem the plug solves and the art had already recognized Al–Si spiking at contacts.

A defendant that omits this reference will likely lose on claim 1.

7. Secondary considerations and the best non‑obviousness story

To be balanced, the strongest Patent‑Owner arguments are:

1. Teaching away. '528 is preoccupied with preserving breakdown voltage (claim 9: V_BD > 65 V) and preventing punch‑through; the '830 Background admits the industry deliberately used deep N+ junctions (1.2–1.8 µm) to increase breakdown voltage and to avoid Al–Si spiking. A Patent Owner will argue the art pointed toward deep junctions and wide drift regions, away from the shallow, tightly scaled junctions of claim 1. Rebuttal: '528's whole thesis is that a scaled transistor with preserved breakdown is achievable (via the pocket implant), so the field was moving in the claimed direction; and the '830 Background itself concedes the market was pushing toward smaller droplets, lower drive energy and thinner linewidths, which supplied the motivation.
2. Range arguments. A Patent Owner may contend the 0.2–0.75 junction‑depth/gate‑length ratio produces a new and unexpected result (higher packing density without degradation). This fails absent comparative data showing criticality of the endpoints — the specification offers none, which itself is telling.
3. The combination adds cost. Adding a plug step and switching the dielectric is more processing, which a Patent Owner can frame as contrary to the art's economy motivation. Rebuttal: the plug cost is offset by the yield it buys at shallow junctions, and '396 shows BPSG planarization was already standard.

Net assessment: each claim 1 limitation is individually known or a routine design choice, and the motivation chain is unusually well documented in the references themselves (density pressure → scaled transistor → shallow junctions → contact spiking → plug/barrier; and resolution pressure → finer lithography → BPSG PMD). Claim 1 and claim 7 look strongly vulnerable to a well‑constructed § 103 challenge, conditional on producing a plug reference and confirming that US 6,666,545 is § 102(e) art ("by another").

8. Practical notes for the invalidity/validity posture

• No IPR path now. The '830 expired July 28, 2023 (anticipated expiration per the page) and the one verified suit closed June 18, 2021, so the § 315(b) one‑year window has long run. Validity would arise only in a revived/enforcement context, and only pre‑expiration damages would be at issue.
• Priority discipline. Confirm that TW 091138067A supports every limitation of claims 1 and 7 (particularly the numeric ratios and the BPSG ranges). If any limitation lacks TW support, the effective date shifts to July 28, 2003 — which would not by itself revive the "Cited By" documents, but it would remove the '545's § 102(e) cushion only if the '545's own art date also moved, which it does not.
• The '545 "by another" check is a threshold task: pull the '545's front page from a primary source and compare its inventive entity with {Liu, Liou, Chen, Hu}. If there is overlap, Combination A collapses to Combination B/C, and the analysis becomes noticeably weaker.

Sources relied on: the patent page itself, https://patents.google.com/patent/[US6841830](/patent/US6841830)/en (prior-art keywords: drain, bpsg, oxide semiconductor, metal oxide, field effect; prior‑art date 2002‑12‑31) and its claims; https://patents.google.com/patent/US6102528 and https://patentimages.storage.googleapis.com/93/69/d4/e5c82d46747f8f/US6102528.pdf (Xerox '528); http://www.everypatent.com/comp/pat6102528.html (claims 8–9 of '528); https://patents.google.com/patent/[US6666545B2](/patent/US6666545B2)/en and https://uspto.report/patent/grant/[6,666,545](/patent/6666545) ('545); https://patents.google.com/patent/[US6315396B1](/patent/US6315396B1)/en and https://uspto.report/patent/grant/[6,315,396](/patent/6315396) (Canon '396, PSG/BPSG interlayer ≈7000 Å); https://patents.google.com/patent/JPH04307255A/en (Xerox monolithic TIJ printhead module — As to inhibit Al–Si reaction and reduce junction spikes, reflow glass, vias), which I infer to be the counterpart of US 5,075,250 on the page's "Similar Documents" list; EP 0 909 649 A2/A3 (Xerox '528 family); and the general 1990s‑CMOS PMD literature confirming BPSG as PMD and tungsten‑plug CMP practice.

If it would help, I can next attempt to locate a specific pre‑2002 refractory‑metal‑plug reference to close the claim 1 gap, and verify the '545 inventive entity.