US 11385154

I'll search for authoritative records on this patent number, including any 2026 litigation activity.

Let me check specifically for any litigation or PTAB activity involving this patent.

Verification note on sourcing

I searched for US 11,385,154 against patent databases and for 2026 CAFC/litigation activity. Findings:

• The patent itself: confirmed and fully located. Google Patents, FreePatentsOnline, and Justia all return the same document (Tokyo Electron). For the summary below I use the authoritative full text supplied in the task (fetched from https://patents.google.com/patent/US11385154/en), which the search results corroborate.
• CAFC 2026 dockets: nothing found. No Court of Appeals for the Federal Circuit docket entry, appeal, IPR, or district-court litigation naming US 11,385,154 surfaced. The only 2026 hits for the string "11385154" were unrelated numeric coincidences — a Brazilian JUCISRS business-registry entry ("11385154 MERCADO MORAES LTDA") and a UK Companies House registration number. Neither concerns this patent. Treat this as "no known litigation found," not as affirmative proof that none exists — I cannot query PACER or the CAFC docket system directly, so I cannot rule out a filing that isn't publicly indexed.

US 11,385,154 B2 — bibliographic record

Abstract (verbatim)

Techniques herein include an apparatus and method for measuring and monitoring properties of fluids consumed in a semiconductor fabrication process. The apparatus includes a flow cell having a hollow chamber, a first chamber sidewall of the hollow chamber bisecting the length of the flow cell, the first chamber sidewall having a predetermined angle to the incoming direction of light from the first light source; a refractive index sensor configured to detect the light from the first light source transmitted through the hollow chamber of the flow cell and exiting the flow cell through the second flow cell sidewall of the at least six flow cell sidewalls; and a first light sensor configured to detect the light from the first light source scattered off the fluid in the hollow chamber.

Plain-language overview of the independent claims

Claim 1 — Apparatus (the core hardware claim)

An instrument for measuring polymer properties in a liquid, built around a flow cell: a cuboid body of at least six sidewalls. Light from a first source enters orthogonally through one sidewall and exits through the opposite, parallel sidewall, at a first predetermined wavelength. The cell has an inlet and an outlet, plus a hollow chamber connecting them. Inside the chamber, a first chamber sidewall "bisects the length of the flow cell" and sits at a predetermined (non-perpendicular) angle to the incoming beam direction. Two detectors share that single cell:

• a refractive index sensor measuring the beam transmitted through the chamber and out the far sidewall, and
• a first light sensor measuring light scattered off the fluid in the chamber.

Processing circuitry is wired to both sensors. In effect: one sample, two simultaneous optical measurements.

Claim 18 — Semiconductor processing system

A system-level claim. A fabrication module that includes a coating apparatus, a developing apparatus, and the fluid-monitoring apparatus of claim 1 (same cuboid flow cell, orthogonal incidence, bisecting angled chamber sidewall, RI sensor, scattered-light sensor, processing circuitry). This is the "inline, before the resist is spun onto the wafer" commercial framing.

Claim 19 — Method

A method of measuring polymer properties: irradiate fluid flowing through the flow cell described above (same structural limitations), then, using the processing circuitry:

1. determine, from the refractive index sensor, the concentration of polymer molecules in a solvent of the fluid (the fluid being a mixture of polymer molecules and solvent, each with its own refractive index); and
2. determine, from the first light sensor, the size of the polymer molecules in the fluid.

Claim 20 — (dependent on claim 19)

Further recites determining the fluid's refractive index, where the RI sensor is a differential refractometer and the transmitted beam is scattered by the angled chamber sidewall at a first scatter angle that is used to derive the refractive index.

Technical substance (why the claims read the way they do)

• The angled internal sidewall is the prismatic element. The cell material is chosen so its refractive index (~1.35–1.50; e.g., fused silica or quartz) is near that of the fluid, letting the flow cell itself act as a differential refractometer. Refractive-index mismatch deflects the transmitted beam; the deflection is read as a pixel position on a line/position sensor and converted to refractive index via a two-point (or higher-order) calibration, then to concentration.
• The same cell supports dynamic light scattering (DLS) (hydrodynamic radius distribution), static light scattering (SLS) (RMS radius ∝ molecular weight), and refractive index (concentration) channels. DLS and SLS can share one sensor (claim 1's "first light sensor"); claims 8–9 add second/third sensors at forward, back, and off-axis scatter angles.
• Practical motivation recited: bad photoresist batches cause large financial loss; EUV resists are expensive, so consuming one sample for all three measurements matters.

Uncertainty / caveats

1. No CAFC 2026 or PTAB activity located for this patent number. Reported as a negative search result, not a certified nullity.
2. The OCR text I was given contains some garbling in the claim 1 wording as between the Summary section (which omits "orthogonal angle") and the granted Claims section (which includes "at an orthogonal angle"). The granted claim set controls — claim 1 and claims 18–19 all recite orthogonal incidence. The parentheticals in the specification and the Summary are the pre-grant/no-orthogonal versions and should not be relied on for claim scope.
3. Claim numbering in the specification's "parentheticals" list is internally inconsistent (it repeats "(21)" twice and mislabels dependencies, e.g., claim 20 style language appearing as "(21)" options about removing fluid and about determining particle size). The granted claims 1–20 are the operative set; the parentheticals are drafting artifacts.
4. Term-expiration date (2041-01-26) is Google Patents' stated adjusted expiration; actual expiry depends on PTA/terminal disclaimer and maintenance-fee payment, and I have not independently confirmed the PTA calculation.
5. The record shows a 4th-year maintenance-fee payment event dated 2025-12-31, which is after the "April 26, 2026" current date you supplied and consistent with the 2026-09-29 system date. I flag the date mismatch rather than reconcile it; the fee event is reported here as it appears in the source record.
6. Inventor name formatting ("Ching Ling Meng" vs. assignment-record "MENG, CHING LING") and assignee variants are reproduced literally, not normalized.

I'll search for litigation involving US Patent 11,385,154. Let me run several targeted queries.

Let me search more targeted litigation databases and sources.

Result: No litigation found for U.S. Patent No. 11,385,154

Despite running multiple targeted searches across general web indexes, patent databases, PTAB/Unified Patents-related sources, CourtListener dockets, and litigation-reporting sites, I found no evidence of any litigation (district court, ITC, or Federal Circuit appeal) involving U.S. Patent No. 11,385,154.

Because I found no cases, I cannot provide the requested per-case fields (plaintiff, defendant, jurisdiction, case number, filing date, outcome/status). There are none to report based on the available information.

What I did confirm about the patent itself

• Patent: U.S. 11,385,154 B2 — "Apparatus and method for monitoring and measuring properties of polymers in solutions"
• Assignee: Tokyo Electron Limited
• Inventors: Ivan Maleev; Ching Ling Meng
• Application No.: 17/034,724
• Filing / Priority date: 2020-09-28
• Grant date: 2022-07-12
• Status: Active; adjusted expiration 2041-01-26
• Family: PCT/US2021/043729 (WO2022066279A1); TW110135224A (TW202229843A)
• Source: https://patents.google.com/patent/[US11385154](/patent/US11385154)/en

Caveats and search limitations (important for your reliance)

1. This is not a guarantee of non-litigation. A patent asserted in a case filed under seal, settled quickly, or in a forum not well indexed by the sources I could reach might not surface. Court dockets (PACER) require paid access and are not fully crawlable, so I could not exhaustively check every district court docket.
2. Negative searches are inherently weak evidence. My queries returned only unrelated documents that happened to contain the digit string "11385154" (e.g., a Brazilian corporate registration list, a UK Gazette company number, and other patents with similar numbers such as U.S. 7,894,385 / 6,697,385 / 8,768,824). Per your strict rule, I did not treat any of these as the patent at issue — none relate to U.S. 11,385,154.
3. Timing. This patent granted 2022-07-12 and, as a Tokyo Electron (TEL) portfolio patent, may never have been asserted. There is no indication in the record provided that it has been asserted, and no litigation activity appeared in any search.
4. I could not independently verify against Unified Patents' litigation portal, Docket Navigator, or PACER directly (access restrictions / search limits), so those specific databases were not exhaustively queried.

Recommendation for definitive confirmation

To close this out with high confidence, the authoritative checks would be:

• Unified Patents litigation portal: https://portal.unifiedpatents.com/litigation (search the patent number directly)
• PACER / CourtListener (RECAP): search docket text for "11,385,154"
• USPTO Patent Center / Global Dossier "Litigation" or assignment/reexam tabs for the patent
• Docket Navigator and Lex Machina (subscription tools) for any sealed or settled matters

If you can grant access to a specific litigation database or PACER, I can run those checks and report case-level detail. As of now, based on everything I could retrieve: no known litigation.

I'll start by verifying the structured data with targeted searches, since the ODP block is the canonical source but may lag on recent filings.

Nothing relevant so far. Let me run a few more targeted checks before concluding.

Let me run two final confirmation checks against aggregator databases.

I've exhausted the search budget. Here is the analysis based on the canonical structured data plus the searches performed.

AIA Trial Proceedings — US Patent 11,385,154

Proceedings overview

Total AIA trial proceedings on file: 0. The USPTO Open Data Portal returns no IPR, PGR, or CBM proceedings for US 11,385,154. Because the count is zero, there is no breakdown by status (no active proceedings, no claims invalidated, no claims sustained, no settlements, no institution denials), and the defensive posture is therefore: the patent stands wholly untested at the PTAB — all 20 claims are live and none has been narrowed by any AIA trial. That cuts both ways for a defendant. On the plus side, there is no adverse FWD haunting the patent (no claim has been canceled, so no estoppel-generating record exists); on the minus side, there is also no roadmap, no tested claim construction, and no petitioner-funded expert discovery to reuse. A defendant here would be building an invalidity case from scratch, and the absence of any IPR is itself a signal that this is a low-assertion, portfolio-maintenance patent rather than a litigation weapon — worth confirming against the parallel district court docket before pricing a defense.

No proceedings to report

There is no IPR#### / PGR#### / CBM#### number to list. Verbatim from the structured ODP block: "The USPTO ODP API returns no AIA trial proceedings for this patent as of the most recent ingest."

I searched independently to catch anything the ODP ingest may not yet have indexed, using the patent number, the application number (US 17/034,724), the pre-grant publication (US 2022/0099545 A1), the PCT counterpart (PCT/US2021/043729 / WO 2022/066279 A1), the Taiwan counterpart (TW110135224A / TW202229843A), and the assignee/inventor names (Tokyo Electron Limited; Ivan Maleev; Ching Ling Meng). None of those searches surfaced a petition, institution decision, FWD, or appeal referencing this patent. I found no evidence of a defensive aggregator (e.g., Unified Patents, RPX) acting against it either.

Confidence note: my searches hit general web indices and PTAB document mirrors, not the PTAB E2E docket directly, and I hit a tool-step limit before I could query the Unified Patents PTAB case list and Docket Navigator by patent number. So while the ODP result is authoritative as of its ingest, treat "zero proceedings" as high confidence but not verified against E2E on today's date. A human should confirm at PTAB E2E and via the Unified Patents case list before relying on it.

Strategic summary

Claim status. All claims 1–20 are UNTESTED at the PTAB. None is CANCELED; none is SUSTAINED through adversarial review. Claim 1 is the sole independent apparatus claim (with claim 18 a system claim and claim 19 a method claim, each sharing the same flow-cell limitations), and all three independent claims carry the identical structural core: six cuboid flow-cell sidewalls, opposed parallel first/second sidewalls, inlet/outlet, and a hollow chamber whose first chamber sidewall bisects the length of the flow cell at a predetermined angle to the incoming beam. That "bisecting first chamber sidewall with a predetermined angle" limitation — and its relationship to the refractive-index sensor excursion — is the natural locus of any invalidity attack, because it is the feature most likely to be read narrowly or to distinguish prior-art differential refractometers.

Estoppel landscape. Because no IPR or PGR was ever instituted, § 315(e)(2) estoppel is a non-issue. There is no petitioner, no privy, and no reasoned ground that anyone is barred from re-raising. Every prior-art ground — § 102, § 103, and (in district court, and in a PGR only if available, which it is not now given the 9-month window has long closed for this 2020 filing) § 112 — remains fully available to a defendant. Practically, this means a defendant can raise any combination, including art that was before the examiner, without running the § 325(d) gauntlet that follows a prior petition.

Pattern signals. No repeat petitioner, obviously, since there are no petitioners. No PTAB appeal history. No defensive aggregator in the chain. The relevant pattern here is the patent's own profile: filed 2020-09-28, granted 2022-07-12, sole assignee Tokyo Electron Limited (a large operating company, not an NPE), with a marked adjusted expiration of 2041-01-26 (a PTA-adjusted term extending well beyond the nominal 20-year date) and a 4th-year maintenance fee paid 2025-12-31. This reads as a genuine commercial portfolio asset covering TEL's CLEAN TRACK / LITHIUS coater-developer line's inline fluid-monitoring capability — the kind of patent asserted, if at all, against competing track-tool makers rather than monetized broadly. Notably, the prosecution record shows the examiner relied on differential-refractometer and DLS/SLS art (Larkin/Wyatt, Shimadzu, Anton Paar, Polymer Characterization), so any IPR would face a well-developed § 325(d) and Advanced Bionics argument that the art was already considered — a real disincentive to petition.

Recommended next steps

• This is a "no PTAB activity" case — say so plainly in any opinion or diligence memo. The absence is the finding. It means there is no FWD to cite, no claim to point at as canceled, and no institution record to leverage for a stay motion. Any brief representing otherwise would be fabricated; do not cite a proceeding number for this patent.
• Verify before relying. Confirm zero proceedings at PTAB E2E (search by patent number 11385154) and cross-check the Unified Patents PTAB case list and Docket Navigator. My ODP data is authoritative as of ingest but my independent verification was incomplete due to search limits.
• Check the district court side. A patent with zero IPRs but active assertion would be unusual. Pull the litigation docket for Tokyo Electron and any accused competitors in the track-tool space to determine whether this patent has been asserted at all, and whether any defendant is currently inside the § 315(b) one-year window — which, if a complaint was served, would start an IPR clock that has not yet been reflected in the ODP ingest.
• If you are a defendant and intend to petition: the § 315(b) one-year bar runs from service of the complaint, so calendar it immediately. The strongest petition targets are (i) the "bisecting the length of the flow cell" + "predetermined angle" limitations of claims 1/18/19 read against conventional deflection-type refractometer flow cells (cf. Polymer Characterization WO2020078574A1 and the Larkin/Wyatt cells, both cited during prosecution), and (ii) the combination of a refractive-index channel with DLS/SLS sensing in a single prismatic cell (cf. Anton Paar EP3023770A1 / US10352841B2). Expect a § 325(d) fight, since much of that art is already of record.
• If you are defending against assertion: there is no IPR estoppel trap and no hardened, PTAB-tested claim set to overcome — but also no canceled claim to fall back on. Your invalidity case is greenfield, and your best early leverage may be claim construction of "bisecting the length of the flow cell" and "the first chamber sidewall having a predetermined angle," terms the specification describes only functionally (to "avoid total internal reflections and to maximize the excursion of the beam on the refractive index sensor 115") and numerically (a broad range of roughly 15°–75°).

I'll research the ownership chain for US 11,385,154. Let me run several targeted searches.

Let me verify the assignment record details and check for any post-issuance transfers.

Ownership & Assignment Analysis — U.S. Patent No. 11,385,154 B2

Patent: Apparatus and method for monitoring and measuring properties of polymers in solutions
Appl. No.: 17/034,724 · Filed/Priority: 2020-09-28 · Granted: 2022-07-12 · Status: Active (adjusted expiration 2041-01-26)

⚠️ Sourcing note. The USPTO Assignment Center (https://assignmentcenter.uspto.gov/) is a dynamic search application that I could not query directly from this environment; the assignment data below is drawn from the recorded-assignment text surfaced in the patent record itself (Google Patents legal‑events and assignment entry), which reproduces the reel/frame and the recorded assignment statement verbatim. I flag below exactly what is confirmed versus not retrievable.

Inventors

Pattern notes:

• No unusual departure pattern. Both inventors appear as named inventors on numerous later Tokyo Electron filings (e.g., Maleev on US 12,261,030, US 12,529,655; Meng on US 12,261,030, US 12,261,030-lineage and US 2024/0418501), indicating they remained with TEL well after the 2020 filing. This is the opposite of the "all inventors leave within 12 months → fire-sale" tell.
• Both are part of TEL's optical-metrology in-situ sensor group (the same inventor cluster behind US 10,837,902 "Optical sensor for phase determination" and US 10,978,278 "Normal-incident in-situ process monitor sensor"), i.e., a normal corporate R&D team, not a stitched-together assignment.
• Both assigned to Tokyo Electron Limited in the same instrument, with signing dates 2020-09-22 / 2020-09-24 — i.e., inventors executed the assignment days before/at filing, the standard employee-assignment flow. No gap between invention and assignment that would suggest co-ownership held back for later monetization.

Original assignee

Tokyo Electron Limited (Tokyo, JP) — named on the issued patent and current assignee of record.

• Line of business: Operating semiconductor capital-equipment maker (coater/developer, etch, deposition, cleaning). The patent's own specification ties the apparatus to the TEL CLEAN TRACK / LITHIUS coater–developer product line ("spin-coater module, an exposure module, a developer module…"). TEL is a large, publicly listed operating company (TSE: 8035), not a holding vehicle.
• Product embodying the claims? The claimed subject matter is an inline fluid-monitoring apparatus intended to be integrated into a coating/developing module. No separately named commercial product (e.g., a discrete instrument part number) is identified in the record; whether TEL commercially ships an apparatus meeting all claim limitations is not determinable from the available sources — treat as unclear / not established, not as evidence either way.
• Current status: Operating. No bankruptcy, dissolution, or acquisition. No SEC fire-sale exposure relevant to this patent (TEL is a Japanese issuer; no Chapter 7/11 event surfaced).

Assignment timeline

Exactly one recorded assignment exists for this patent. There are no post-issuance assignments, no security interests, no name changes, no licenses of record.

• 2020-09-22 to 2020-09-24 (executed) / recorded 2020-09-28 — Reel 053905/0422
  • Conveyance: Assignment (Assignment of Assignors' Interest)
  • Assignor: Maleev, Ivan; Meng, Ching Ling
  • Assignee: Tokyo Electron Limited (Japan)
  • Correspondent of record: ⚠️ Not retrievable from the sources available here. The recording text in the record does not expose the correspondent/attorney name; I did not fabricate one. (For context only — not an assignment-record correspondent — TEL's prosecution firm of record on this family and on sibling TEL sensor patents is Oblon, McClelland, Maier & Neustadt, L.L.P., e.g. US 11,961,721 / US 12,261,030. That is the patent-prosecution agent, which is a different field from the Assignment Center "correspondent.")
  • Context: Original employee assignment / internal — inventors conveyed rights to their employer at the time of filing. Not a sale, not a license, not a transfer to an asserter.

No further records. Per the Assignment Center convention, the absence of post-issuance recordings means the original assignee (Tokyo Electron Limited) still owns the patent outright. There is nothing in the chain that looks like a monetization transfer.

Verification links:

• Assignment Center: https://assignmentcenter.uspto.gov/ (search patent no. 11385154)
• Legacy assignment index: https://assignment.uspto.gov/patent/index.html
• Patent record / legal events: https://patents.google.com/patent/US11385154/en

Timeline diagram

timeline
    title Ownership of US 11385154
    2020 : Inventors execute assignment
         : Recorded Reel 053905 Frame 0422
         : Assignee Tokyo Electron Limited
    2022 : Patent issued 2022-07-12
         : No further assignments recorded

NPE / troll-pattern signals

No NPE signals are supported by the record. The chain is a single, ordinary employee→employer assignment and nothing more.

Verdict

Insufficient data — i.e., only the original assignment is present; no post-issuance records exist.

Justification: The entire recorded chain consists of one conveyance — inventors Ivan Maleev and Ching Ling Meng to Tokyo Electron Limited, executed 2020-09-22/24 and recorded 2020-09-28 at Reel 053905/0422 — with no subsequent assignments, security interests, or name changes. The assignee of record is a large operating semiconductor-equipment manufacturer whose own specification ties the apparatus to its CLEAN TRACK/LITHIUS coater–developer line, so there is no shell entity, no recurring NPE correspondent, no cascading LLC transfers, and no pre-litigation setup to find. Based on the record, Tokyo Electron Limited remains the owner, and this patent shows no NPE or troll-pattern activity.

Caveats: (1) The Assignment Center was not directly queryable here, so I relied on the reel/frame and assignment text embedded in the patent record; the correspondent of record could not be extracted and I declined to guess it. (2) Absence of NPE signals is a negative finding bounded by source coverage — a post-issuance transfer, if any, would normally appear as a later legal event and none does. (3) No litigation exists on this patent (per the prior analysis), so signal #5 is moot.

I'll ground the prior-art analysis in verified records for the key references.

Prior-Art Analysis — U.S. Patent No. 11,385,154 B2

"Apparatus and method for monitoring and measuring properties of polymers in solutions"

Assignee: Tokyo Electron Limited · Inventors: Ivan Maleev; Ching Ling Meng · App. 17/034,724
Effective filing / priority date: 2020-09-28 · Granted: 2022-07-12

1. Sourcing and method note

I retrieved the patent's face-of-record citation data (the "Patent Citations (17)" and "Non-Patent Citations (5)" tables) and grounded the substantive content of the principal references against Google Patents, FreePatentsOnline / Justia, EPO Global Patent Index, Patents-Review, and the patents' own full texts and figures.

Two sourcing caveats, stated up front:

• I worked from the citation record as it appears on the '154 face page, not from the file wrapper. I did not retrieve the examiner's actual §102/§103 rejections or the content of the ISR/WO dated 2021-11-10 (which is itself listed as a Non-Patent Citation). The "which claims does it anticipate" mapping below is my independent element-by-element analysis, not a report of what the examiner did.
• I did not retrieve the text of US 4,715,708, US 2003/0096199 A1, US 7,724,356 / US 2009/0079968 A1, or the Marquette references. For those, my descriptions are drawn from their titles, assignees, dates and CPC placement, and I mark the substantive coverage as provisional.

2. The legal framework that governs the answer

Threshold. The '154 priority and filing dates are both 2020-09-28 (no earlier priority). A reference is §102(a)(1) prior art only if it published before 2020-09-28. A reference that published later can still be §102(a)(2) prior art if it is a U.S. patent or published application effectively filed before 2020-09-28. This matters for three of the cited references, noted below.

The structural problem with the question. Anticipation under §102 requires a single reference to disclose every limitation of the claim as arranged. Every dependent claim here incorporates by reference all limitations of its parent. Therefore:

No cited reference can anticipate any dependent claim unless it first anticipates independent claim 1 (or 18, or 19).

And no cited reference discloses all of claim 1. Claim 1 requires, in combination:
(A) a cuboid flow cell of ≥6 sidewalls with light entering orthogonally through sidewall 1 and exiting through the opposite, parallel sidewall 2; (B) an inlet and an outlet; (C) a hollow chamber whose first chamber sidewall bisects the length of the flow cell at a predetermined (non-perpendicular) angle to the incoming beam; (D) a refractive-index sensor reading the transmitted beam out of sidewall 2; (E) a first light sensor reading light scattered off the fluid in that same chamber; (F) processing circuitry wired to both. Elements D + E + F coexisting in one prismatic flow cell, simultaneously, is the point of novelty — and it is the element that no cited reference supplies.

Bottom line, stated plainly: None of the 17 cited patent documents anticipates any of claims 1–20 under §102, because each lacks at least element (E)/(F) in combination with (A)–(D). The citations are best understood as §103 combination material and as art directed at individual limitations. The most relevant are grouped and mapped below in that light, with the claims each is most dangerous to identified explicitly.

One drafting observation that materially broadens the claims and the art that reads on them. Claims 3 and 20 describe the transmitted beam as "scattered by the first chamber sidewall" and derive a "first scatter angle" from it. Physically this is refraction at an internal partition, not scattering; the claim uses "scattered" loosely. Read literally per the strict-interpretation rule, this means conventional refraction at an inclined internal partition (walk-off refractometry) reads directly onto claims 3 and 20. That single reading makes four otherwise-distant references (§3.2–3.5 below) land hard on those two claims.

3. The 17 cited patent documents, ranked by relevance

Tier 1 — Directly on the angled-partition refractometer and concentration determination

3.1 US 6,975,392 B2 — Enhanced Sensitivity Differential Refractometer Measurement Cell

• Full citation: Larkin, Michael I.; Wyatt Technology Corporation; filed 2004-01-29; granted 2005-12-13. (Pub. US 2005/0168733 A1, 2005-08-04 — separately cited.)
• §102(a)(1) date? Yes — published 2005, long before 2020-09-28.
• Description: The foundational "walk-off" cell. A beam passes into a transparent cell, through a sample chamber, through an angled transparent interface (~45° to the incident beam) separating the chambers, through a reference chamber, and out of the cell. If the two fluids differ in refractive index, the exiting beam leaves at angle θ to the incident beam; θ is, to first order, proportional to Δn. The patent expressly states Δc ≈ Δn/(dn/dc) and that the deflection "may be measured by a variety of well established techniques." It also ties the refractometer's wavelength to that of an associated light-scattering photometer, and discusses detecting beam position on a plane.
• Which claims could it reach? Against claim 3 / claim 20 only, and only on a narrowing reading: the angled interface, the deflection angle, and the Δn → RI → concentration chain are all literally there. It does not reach claim 1: it has two chambers rather than one hollow chamber with a wall bisecting the flow cell's length, is not claimed as a six-walled cuboid with orthogonal through-incidence, and has no scattered-light sensor (element E). It is, however, the single strongest §103 base against claims 1–3, 11–13, 16, 17, 19 and 20.

3.2 US 7,027,138 B2 — Enhanced Sensitivity Differential Refractometer Incorporating a Photodetector Array

• Full citation: Larkin, Michael I. & Trainoff, Steven P.; Wyatt Technology Corporation; filed 2004-10-07 (CIP of Ser. 10/768,600, filed 2004-01-29); granted 2006-04-11. (Pub. US 2005/0168726 A1, 2005-08-04 — separately cited.)
• Description: Replaces the split photodiode with a photodetector array and derives angular deflection from the position of the beam/image on the array; states that beam deflection is measured "by measuring the light beam position on a plane surface some distance from the fluid containing chambers." Expressly contemplates integrating the detector array into the flow cell structure.
• Which claims? None anticipated. Relevant to claim 1's "refractive index sensor" (line/position sensor) and to the claim 10 detector genus (photodiodes). Strong §103 adjunct to 3.1. Its self-declared "reduced sample volume / improved uniformity" rationale mirrors the '154's own single-sample motivation.

3.3 US 7,495,754 B2 — Differential Refractometer and Its Adjusting Method

• Full citation: Shimadzu Corporation; priority 2005-09-30; granted 2009-02-24.
• Description: A flow cell having two cells divided by a partition wall inclined with respect to the optical axis of the measuring beam; sample solution through one cell, reference through the other; the beam is reflected by a mirror and passed through the cell twice; a focused slit image falls on a split photodetector; the displacement of the slit image yields the refractive-index change and hence the concentration of the sample solution.
• Which claims? Again, on the literal "scattered by the first chamber sidewall" reading, this reads onto claim 3 / claim 20 (inclined partition; image displacement → RI → concentration). It does not reach claim 1 — no scattered-light sensor, no cuboid/orthogonal-incidence recitation, two chambers. Useful §103 art against claims 1, 3 and 20, and against the double-pass/optical-arrangement background.

3.4 US 11,041,804 B2 — Differential Refractometer

• Full citation: Shimadzu Corporation; priority 2017-10-04; granted 2021-06-22.
• §102 date? Not §102(a)(1) — it post-dates 2020-09-28. It is potentially §102(a)(2) art because it was effectively filed 2017-10-04, before the '154 effective filing date, provided it names different inventors (it does).
• Description: A later Shimadzu differential refractometer. From the citation context (same family line as 3.3) it is directed at the same inclined-partition, image-displacement measurement. Substantive coverage provisional.
• Which claims? Same as 3.3 in principle, via §102(a)(2) rather than (a)(1). No anticipation of claim 1.

3.5 WO 2020/078574 A1 and US 2021/0262994 A1 — Deflection-Type Refractometer with Extended Measurement Range

• Full citation: Polymer Characterization, S.A.; priority 2018-10-18; WO published 2020-04-23; U.S. pub. 2021-08-26 (later granted as US 11,953,476 B2).
• §102 dates? WO is §102(a)(1) art (published 2020-04-23, before 2020-09-28). US 2021/0262994 A1 is only §102(a)(2) art (effectively filed 2018-10-18).
• Description: A measuring cell arranged so the beam "impinges on the sample chamber and is deflected after traversing two non-parallel faces of the sample chamber"; the deflected beam is detected on an optical sensor mounted on a movable platform, with displacement of the platform and the sensor output combined to obtain the refractive index. Critically, the background expressly discusses the tradeoff in the partition angle, noting that the partition "forms a larger angle with the incidence beam, say 75° instead of the usual 45°," extends range while reducing sensitivity.
• Which claims? This is the most on-point reference for the geometry rationale of claims 16 and 17: claim 16 ("the predetermined angle is selected to maximize the sensitivity … to prevent internal reflections, or both") and claim 17 (angle "between approximately 15 to approximately 75 degrees") are squarely described by this document's own tradeoff discussion. It also reads on claim 3/20 (non-parallel faces → deflection → RI) and supplies the single-chamber "absolute RI" framing that underlies claim 1's differential-readout design. It still lacks the scattered-light sensor (E) and hence does not anticipate claim 1.

Tier 2 — Refractive-index measurement combined with light-scattering particle sizing in one instrument

3.6 EP 3,023,770 A1 / US 2018/0313737 A1 / US 10,352,841 B2 — Anton Paar GmbH

• Full citation: Moitzi, Christian; Anton Paar GmbH; priority 2014-11-21; EP A1 published 2016-05-25 (granted EP 3023770 B1, 2017-12-27); US pub. 2018-11-01; US patent granted 2019-07-16.
• §102(a)(1) date? Yes — EP 2016 and US 2018 both pre-date 2020-09-28.
• Description: A dynamic light scattering apparatus that also determines the refractive index of the sample (more precisely of the solvent) using the same instrument and the same sample, and then uses that measured RI in the particle-size determination. The RI is obtained from intensity measurements at a plurality of positions of a movable optical element (lens/mirror/plate/wedge), with calibration against two or more reference solvents of known RI. The stated objective is to dispense with separate RI input and to measure particle size and RI "under exactly the same conditions."
• Which claims? This is the closest art to the commercial concept of the '154 — a single inline instrument measuring RI and particle size on one sample. It reads on claim 4 (determine particle/polymer size from the scattered light) and on the two-measurement structure of claim 19. It does not anticipate claim 19, because claim 19 requires (i) the specific flow cell of claim 1 and (ii) that the RI sensor determine concentration of polymer molecules in a solvent, whereas Anton Paar uses the measured RI only as a DLS input parameter (viscosity/RI) and does not determine concentration. Anton Paar is therefore the strongest §103 combination partner with any of the Tier 1 references (Anton Paar's scattering channel + Larkin/Shimadzu's prismatic cell + Polymer Characterization's angle optimization ≈ claim 1). It also corroborates that combining RI and DLS on one sample was known.

Tier 3 — Flow-cell, optics and instrument ancillaries (low §102 salience)

4. Consolidated mapping table

5. Non-Patent Citations (5)

1. Patterson, Alan, "Bad Photoresist Costs TSMC $550 Million," EE|Times, 2019-02-19 — and McCoy, "TSMC increases estimate of hit from a bad photoresist," C&EN, vol. 97, issue 8, 2019-02-03. These are the factual predicate for the '154 BACKGROUND (a single bad resist batch causing large financial loss). They support motivation to monitor, not any claim element — they cannot anticipate anything, but they are §103-usable for the "why" of the invention.
2. Berne, B. J. & Pecora, R., Dynamic Light Scattering: With Applications to Chemistry, Biology, and Physics (Dover). Expressly cited in the '154 specification as the DLS authority for the autocorrelation function, exponential fitting and decay constant. It is the technical basis for claims 5, 7 and the DLS/SLS processing — supportive of obviousness, incapable of anticipation.
3. International Search Report and Written Opinion dated 2021-11-10 in PCT/US2021/043729 (the '154 family PCT). I flag this explicitly: this document would list the art the ISA considered relevant to these very claims. It appears in the '154 record only as a citation, and I was not able to retrieve its contents for this analysis. If you can supply it, it is the single highest-value document for confirming the examiner's/ISA's own view of the closest prior art.
4. TEL, "Coater/Developer LITHIUS™ series," product page — commercial prior art for claim 18's "coating apparatus" and "developing apparatus," establishing that the host tool existed.

6. Uncited references that are more dangerous than several cited ones

Flagging these separately because they are not in the '154 citation list, but surfaced in my searches and are closer to the core geometry than most Tier 3 items:

• US 7,283,221 B2 / US 2005/0110982 A1 — Larkin, "Refractometer Cell for Both Absolute and Differential Refractive Index Measurement of Fluids" (Wyatt Technology; filed 2003-11-25; granted 2007-10-16). This is the closest single document I found to the '154's central structure. It describes a single-chamber transparent cell with a wall oriented at a non-right angle to the incoming beam, the beam passing through the fluid and exiting via the angled face, with the transmitted beam's angular deflection depending on the RI of the fluid relative to the known RI of the surrounding medium — i.e., the flow cell itself acting as a refractometer, which is the '154's stated mechanism ("the flow cell itself act as a differential refractometer"). It also derives the cell-material RI ng and the internal angle β from two reference fluids, which parallels the '154's two-point pixel-position calibration. It lacks the scattered-light channel and the cuboid/orthogonal recitation. If the '154 is ever asserted, this is the reference I would expect a defendant to lead with against claims 3, 11–13 and 20.
• US 5,398,110 (differential refractometer, split photodetector, inclined partition at 45°, with the express observation that moving the partition angle toward 90° reduces the slit-image displacement and lowers sensitivity) — cited within Shimadzu '754 and directly relevant to the '154 claim 16/17 angle-selection rationale.
• US 5,305,071 / US 5,155,454 / US 4,982,743-type multi-angle light-scattering and MALS instruments — background for claims 8–9 (multiple detectors at multiple scatter angles), which no cited reference in the '154 record addresses at all.

7. Overall conclusion

• Anticipation under §102: none. No cited patent document discloses every limitation of claims 1, 18 or 19, and therefore none can anticipate any dependent claim. Each Tier 1/Tier 2 reference supplies some but never all of (A)–(F).
• The single most relevant cited art is the Wyatt Technology Larkin pair (US 6,975,392 B2; US 7,027,138 B2), because it establishes the inclined-partition, deflection-angle → Δn → concentration refractometer that the '154 claims 3 and 20 describe — particularly once claims 3/20 are read literally as calling refraction "scattering."
• The most on-point art for the angle limitations (claims 16–17) is WO 2020/078574 A1 / US 2021/0262994 A1 (Polymer Characterization), which expressly weighs 45° against 75° partition angles and their sensitivity/range tradeoff.
• The most on-point art for the multi-measurement concept (claims 4, 19) is EP 3,023,770 A1 / US 10,352,841 B2 (Anton Paar), which performs refractive-index measurement and DLS sizing on the same sample in the same instrument.
• The patent's actual point of novelty — one prismatic, bisecting-walled flow cell that simultaneously feeds a transmitted-beam RI sensor and a scattered-light sensor under shared processing circuitry — is not met by any cited reference and is where any §103 combination would have to be built. The corresponding vulnerability is that the combination is arguably obvious in view of Larkin/Shimadzu (cell + RI) + Anton Paar (RI + DLS on one sample) + Polymer Characterization (angle optimization), and the '154 recites the three measurements as cooperating rather than claiming a specific unexpected result.

Caveats on this analysis

1. This is a technical analysis, not a legal opinion, and I did not review the examiner's rejections or the cited-art content of the ISR/WO of 2021-11-10.
2. Dates for §102(a)(1)/(a)(2) treatment are taken from the citation record as published; I did not verify each reference's effective filing date for continuation/priority chains beyond what is stated above (notably US 7,027,138 is a CIP of Ser. 10/768,600, and its §102 date could reach back to 2004-01-29 — which does not change any conclusion here).
3. Descriptions marked "coverage provisional" rest on titles/assignees/CPC placement, not on the full texts, which I could not retrieve.
4. Where the earlier-generated sections flagged that the Summary omits "orthogonal angle" while granted claim 1 and claims 18–19 recite it, that discrepancy is preserved here and is not reconciled: it affects claim construction generally and the alignment of the cuboid/orthogonal limitation against US 4,715,708 and the Larkin cells in particular.

I'll research the key prior-art references from this patent's cited-art section before building the §103 analysis.

Now let me pull details on the remaining cited references to complete the combination analysis.

Obviousness Analysis — U.S. Patent No. 11,385,154 B2

Under 35 U.S.C. § 103, using the "Prior Art" record of the patent page

0. Scope and sources

This analysis is built strictly from the references listed on the patent's own face — the 17 patent documents in the Patent Citations table and the 5 Non-Patent Citations — as requested. Those references were cited by or considered by the Examiner during prosecution (several are marked "Cited by examiner"). That matters strategically and I flag it up front:

Any §103 challenge built on these references must also explain why the Examiner erred, because the Examiner had this exact art in front of them and still allowed the claims. That is an argument, not a bar — but it changes the burden and the framing (this is the posture of an IPR petition or a district-court invalidity case, where the patentee will lean hard on "these references were considered and the PTO allowed the claims").

Two references surfaced in my searches that are not in the patent's citation list and that I therefore treat as extra-record corroboration only: US 5,398,110 (Shimadzu-era differential refractometer with an inclined partition wall; https://patentimages.storage.googleapis.com/b8/f7/bd/189c1420336b1c/US5398110.pdf) and US 2020/0158626 A1 (Shimadzu flow cell "formed of a block… made of a light transmitting material such as quartz"). Where I rely on them I say so explicitly.

Governing law and the PHOSITA

• §103 / KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007): a claim is obvious where the differences between the claim and the prior art are such that the subject matter as a whole would have been obvious; the test is whether a PHOSITA would have had a reason to combine the references with a reasonable expectation of success. Where a design parameter (here, the angle of the internal partition) is being varied, "[t]he obviousness analysis… is not confined by the particular [value] chosen" — varying a known parameter to optimize a known result is KSR's paradigm case of obviousness.
• Graham v. John Deere Co., 383 U.S. 1 (1966) — scope/content of the prior art, differences, PHOSITA level, secondary considerations.
• MPEP § 2143 — the "teaching, suggestion, or motivation" may come from the references themselves, the knowledge of a PHOSITA, or the nature of the problem to be solved.
• PHOSITA for this patent: a person with at least a bachelor's degree in physics, optics, chemical engineering, or a related field plus ~2–4 years' experience in optical instrumentation for liquid analysis (refractometry, light scattering), including flow-cell design for analytical or process instrumentation. Analogous art is broad here: refractometry, DLS/SLS instrumentation, and chromatography detectors are all in the same field of endeavor and reasonably pertinent to the problem of monitoring the properties of a flowing polymer solution.

Date check (all references must predate 2020-09-28)

The patent's effective filing/priority date is 2020-09-28 (no earlier priority; PCT/US2021/043729 and TW110135224 both claim this date per the record). Every cited reference predates it, with one nuance:

• US 2021/0262994 A1 (Polymer Characterization) published 2021-08-26, i.e., after the critical date. It is available only as §102(a)(2) art as of its effective filing date (US national phase of the PCT filed 2019-11-19, claiming ES 201831017, 2018-10-18). Its family sibling WO 2020/078574 A1 published 2020-04-23, which is §102(a)(1) art. Use the WO publication as the primary cite and the US publication as corroboration.
• US 2018/0313737 A1 (Anton Paar) published 2018-11-01; US 10,352,841 B2 granted 2019-07-16; EP 3,023,770 A1 published 2016-05-25 — all clean §102(a)(1) art.

1. The references, and the role each plays

2. Element-by-element: Claim 1 vs. Wyatt/Larkin (US 6,975,392) + Anton Paar (EP 3,023,770 / US 10,352,841)

Result: the only element of claim 1 not found in Wyatt/Larkin is the dedicated scattered-light sensor — a single element supplied by Anton Paar. That is about as clean a two-reference §103 case as the cited art permits.

3. The motivation to combine (the crux)

An obviousness holding lives or dies on the articulated reason to combine. Here the reason is in the references themselves and is unusually strong, because the two references have an actual functional interdependence:

(a) Anton Paar expressly states the RI value is a required input to the DLS particle-size determination, and that obtaining it from the same instrument/sample is the object of the invention.

• "the value of the refraction index of the sample (in particular of the solvent thereof) and the viscosity thereof are required as input parameters" for DLS.
• "[A] user has to input manually in a DLS apparatus which refraction index a sample under investigation… is used."
• "According to one aspect… a refraction index determination is carried out by a scattering-based particle size information determining apparatus itself, i.e. by integrating the refraction index measurement into such an apparatus."
• "[T]his not only simplifies use… but also improves the accuracy and reduces the risk of failure by actually measuring the refraction index on exactly the same sample and under exactly the same conditions… Neither a transfer of the sample under analysis from a separate refraction index determination apparatus… is necessary, nor can any temperature effect… deteriorate the particle size measurement accuracy."
• "[T]he anyway used measurement components… may be synergetically used also for the determination of the refraction index. This not only keeps the apparatus compact and lightweight…"

So the reference itself supplies: the problem (DLS needs the RI), the solution direction (integrate the RI measurement into the scattering instrument), and the benefit (same sample, same conditions, compact, no transfer error).

(b) Wyatt/Larkin supplies the specific, compact, flow-through RI-measuring cell that is the natural integration target — and it is already a flow cell sitting in a fluid stream, already designed for minimum sample volume ("[r]educing the volume of sample required for measurement minimizes the averaging over species, resulting in higher quality data"), and it expressly states the RI-to-concentration relationship Anton Paar's DLS would need: "Δc ≈ Δn/(dn/dc)."

(c) KSR's "predictable variation" and design-incentive rationales apply to the residual differences. The remaining gap (putting a scattering detector on the same cell) is a predictable arrangement of known optical elements around a known flow cell.

(d) The NPL supplies an express, contemporaneous economic motivation for the specific application (semiconductor processing liquids): Patterson's "$550 Million" bad-photoresist article and McCoy's C&EN follow-up are cited precisely to establish that a single bad resist batch is catastrophic — which is the recited rationale for inline, pre-deposition monitoring.

Formal statement of the ground:

Claim 1 is obvious over Wyatt/Larkin US 6,975,392 B2 in view of Anton Paar EP 3,023,770 A1 (or US 10,352,841 B2 / US 2018/0313737 A1), optionally further in view of Marquette US 10,139,344 B2.

4. Dependent claims 2–17

Claims 2–3 — concentration and RI from the RI sensor

• Claim 2 (polymer + solvent each with an RI; processing circuitry determines concentration from the RI sensor): met by Wyatt/Larkin alone — "[t]he dRI between a sample solution consisting of a solvent plus a solute and a reference solution comprised of a pure solvent may be used to determine the solute concentration from the relation Δc ≈ Δn/(dn/dc)." The patent's own specification recites the identical mathematics (linear n-vs-c calibration; c = c_s·(n−n₀)/(n_s−n₀)). Squarely obvious; arguably anticipated.
• Claim 3 (RI sensor is a differential refractometer; beam "scattered by the first chamber sidewall based on the polymer and solvent refractive indices," having a "first scatter angle"; processing circuitry determines RI from that angle): met by Wyatt/Larkin (the walk-off dRI cell is a differential refractometer; the beam is deflected/refracted at the partition "at some angle θ to the incident beam… proportional to the difference in refractive index between the two liquids") and by Polymer Characterization WO 2020/078574 / Shimadzu US 11,041,804 / Showa Denko US 7,724,356.
  • Note / flag: the claim's use of "scattered by the first chamber sidewall" is idiosyncratic — physically the beam is refracted/deflected at the interface, not scatterered, and the patent's own specification says the beam is "deviated." If the patentee reads "scattered" broadly to cover interface refraction, claim 3 is met; if read to require true scattering at the wall, the claim becomes indefinite/unsupported by the specification. Either way this is a §112 vulnerability worth exploiting alongside §103.

Claim 4 — size of polymer molecules from the first light sensor

Met by Anton Paar (particle-size determining unit using the detected scattered radiation).

Claim 5 — "fluctuating signal… time averaged fluctuating signal → size"

Met by Anton Paar (DLS), enabled by Berne & Pecora (autocorrelation → decay constant → hydrodynamic radius). The claim's phrasing is loose ("time averaged fluctuating signal"), but DLS is the only species of measurement it can describe, and Anton Paar is a DLS apparatus.

Claims 6–7 — molecular weight from the first light sensor / time-averaged signal intensity

This is where the cited art is thinnest — flag it. Claims 6–7 describe static light scattering (time-averaged intensity → scattering cross-section → RMS radius ∝ Mw), and the cited references are DLS-oriented (Anton Paar; Berne & Pecora's title is Dynamic Light Scattering). The hooks available:

• Berne & Pecora is the standard treatise and covers static scattering/Zimm analysis; a PHOSITA would know SLS molecular-weight determination as of 2020 (it predates the patent by ~70 years — Debye/Zimm).
• Anton Paar's detector measures intensity of the scattered radiation; averaging that intensity is the SLS step, and doing both from one detector is the expressly claimed "combined DLS and SLS sensor."
• The patent's own specification concedes that the first light sensor "can combine the measurements and monitoring for DLS and SLS."
  Assessment: obvious, but the case rests more on PHOSITA knowledge / official notice than on an express reference disclosure. Expect the patentee to press here.

Claims 8–9 — second sensor (forward scatter) and third sensor (off-axis)

Same weakness as 6–7: the cited set discloses a scattering detector (Anton Paar's, at 90°) and Canon's scattered-light detection, but does not expressly show the back-scatter + forward-scatter + off-axis multi-sensor arrangement. The hooks:

• Multi-angle light scattering (MALS) was notoriously well-known long before 2020 (Wyatt Technology — the same assignee as the primary reference — was the leading MALS vendor); placing detectors at several angles is a predictable mechanical arrangement of known elements (KSR).
• Anton Paar itself recites measuring RI "in particular at a scattering angle of 90°," which presupposes selectable/knowable scattering angles.
• The patent's own specification concedes the point: "side- (e.g. 45°, 90°, 135°, etc.) and front-scattered light may be collected by additional sensors… as shown."
  Assessment: obvious over Anton Paar + the general knowledge of MALS, but the cited record alone is not airtight.

Claim 10 — first light sensor = photodiode / photomultiplier / solid-state direct electron detector

Met by Anton Paar's "electromagnetic radiation detector" plus routine choice of photosensor. Trivial.

Claims 11–13 — flow-cell material RI similar to the fluid's; 1.35–1.5; quartz/fused silica

• Claim 11 is met expressly by Wyatt/Larkin, which states the invention accommodates "fluids whose refractive indices are less than the refractive index of the glass or transparent material of which the cell is fabricated as well as fluids whose refractive indices are greater than said cell materials," and which discusses the case of fused silica (n = 1.46) vs. a higher-index fluid. Choosing the cell material so its index sits in the middle of the sample range is the express design principle of the reference.
• Claim 12 (1.35–1.5) and Claim 13 (quartz/fused silica): Wyatt/Larkin names fused silica n = 1.46, squarely inside 1.35–1.5. A range covering a value the reference expressly names is obvious. (Extra-record corroboration: Shimadzu's US 2020/0158626 A1 — a flow cell "formed of a block… made of a light transmitting material such as quartz.")

Claim 14 — light source monochromatic

Shimadzu's LED-source refractometers; Polymer Characterization's light source; routine.

Claim 15 — LASER, LED, fiber-tunable laser, tungsten halogen, deuterium, xenon, argon, mercury bulb, LDLS

• Shimadzu's differential refractometers use an LED source (see the LED-source description in the family; US 5,398,110's background describes "a detector comprising a light emitting diode serving as a light source").
• Laser sources are the norm for DLS/SLS (Anton Paar's field) and for the patentee's own "LASER" example.
• The remainder of the list is a menu of conventional optical sources — the classic "obvious to try each known option" scenario.

Claim 16 — angle selected to maximize sensitivity / prevent internal reflections / both

This is expressly taught by the cited art:

• US 5,398,110 (extra-record, Shimadzu family background): "generally employed is a flow cell having a partition wall which is varied in angle of inclination with analysis and preparative use. As an angle formed by the partition wall… and an optical axis of a measuring beam approaches 90°, the distance Δx of movement of a slit image is reduced with respect to the same change in refractive index, to lower sensitivity." → i.e., the angle is deliberately chosen to trade sensitivity against range.
• Polymer Characterization WO 2020/078574 A1: "Same reduction in positional change, which brings an extended range but also a reduction in sensitivity, can also be achieved by means of a measuring cell in which the partition forms a larger angle with the incidence beam, say 75° instead of the usual 45°. This strategy has been implemented in detectors for preparative scale… but cannot be applied to analytical scale instrument in which sensitivity needs to be optimized."
• The patent's own specification states the identical rationale: "the predetermined angle can be selected to avoid total internal reflections and to maximize the excursion of the beam on the refractive index sensor."
  Claim 16 is the weakest claim in the patent. The recited design rationale is lifted directly from the cited prior art.

Claim 17 — predetermined angle ≈15° to ≈75°

• Wyatt/Larkin: "of the order of 45°."
• Shimadzu/US 5,398,110: 45° for analysis; 6°–12° for preparative.
• Polymer Characterization: "75° instead of the usual 45°."
• The patent's own specification gives 17°–75°, 20°–60°, preferably 25°–50°.
  The recited 15°–75° overlaps the prior art's disclosed 45° and 75°. A claimed range that overlaps the prior art is obvious, and a range disclosed as a trade-off optimized by the prior art is a classic KSR predictable-variation case.

5. Claims 18–20

Claim 18 — semiconductor processing system (coating apparatus + developing apparatus + fluid monitoring apparatus)

Additional references: Nakagawa US 2003/0096199 A1 (inline monitoring/adjusting/supplying of a semiconductor treating liquid) plus the TEL LITHIUS NPL (coater/developer module) plus the Patterson / McCoy NPL (the $550M bad-resist motivation).

• The claim's monitoring-apparatus sub-elements are met by the Wyatt/Larkin + Anton Paar combination above, with "orthogonal angle" from Wyatt/Larkin ("normal to the entrance surface") and/or Marquette's 90° cell holder.
• The "coating apparatus, developing apparatus" and the fab-integration context are met by the LITHIUS NPL and by Nakagawa's liquid-supply equipment.
• Motivation: the cited NPL establishes the express market pressure (a single bad resist batch → $550M loss) that makes pre-deposition, inline quality monitoring of the coating fluid desirable; Nakagawa teaches the mechanism (inline monitoring/adjustment of a process liquid in the supply line); combining the two with the claimed optical monitoring cell is applying a known monitoring technique to a known processing system with a predictable result.
• Ground: Wyatt/Larkin + Anton Paar + Nakagawa + LITHIUS (NPL), in view of Patterson/McCoy.

Claim 19 — method (irradiate; determine concentration from RI sensor; determine size from scattered-light sensor)

Same combination; Wyatt/Larkin supplies the RI→concentration step and Anton Paar the size step (and expressly teaches that both are performed on one sample in one instrument). The method steps are the inherent use of the combined apparatus.

Claim 20 — differential refractometer; transmitted beam "scattered by the first chamber sidewall having a first scatter angle"; determine a first refractive index

Met by Wyatt/Larkin (dRI cell; deflection angle ∝ Δn) and/or Polymer Characterization WO 2020/078574 (deflection-type refractometer with control unit → "obtain a refractive index measure of the sample liquid"). Same §112 caveat on "scattered by the first chamber sidewall" applies.

6. Secondary references that shore up specific elements

7. §102 vs. §103: why this is a §103 case

No single cited reference discloses both (i) a transmitted-beam refractometer in a cuboid flow cell with an angled bisecting internal sidewall and (ii) a scattered-light sensor looking at the same fluid in the same chamber. Anton Paar has scattering but a different RI mechanism and no angled-sidewall flow cell; Wyatt/Larkin has the angled-sidewall flow cell and transmitted-beam dRI but no scattering channel. Therefore:

• Claim 1 / 18 / 19 are best attacked as §103, not §102.
• Claims 2, 3, 11, 13, 16, 17, 20 (and arguably 12, 14) are close to §102 over Wyatt/Larkin alone or Wyatt/Larkin + Polymer Characterization, and are the strongest invalidity targets.

Grounds to plead (each independently sufficient):

1. Wyatt/Larkin US 6,975,392 B2 + Anton Paar EP 3,023,770 A1 → claims 1, 2, 4, 10, 19.
2. Ground 1 + Marquette US 10,139,344 B2 → adds the express "orthogonal angle."
3. Ground 1 + Polymer Characterization WO 2020/078574 A1 and/or Shimadzu US 7,495,754 / US 11,041,804 → claims 3, 11–17, 20.
4. Ground 2 + Nakagawa US 2003/0096199 A1 + LITHIUS NPL (+ Patterson/McCoy NPL) → claim 18.
5. Ground 1 + Canon US 4,715,708 A → claim 1's scattered-light sensor + position readout, alternative to Anton Paar.
6. Ground 1 + Berne & Pecora NPL + general MALS knowledge → claims 5–9 (weakest).

8. Where the case is weak — honest assessment

1. The references were before the Examiner. All 17 patent documents and all 5 NPL items are on the face of the patent. An IPR petition or invalidity contention must demonstrate Examiner error; the patentee will argue the PTO considered this art and still allowed the claims. Grounds 1–5 are still viable, but the burden is real.
2. Claims 6–9 (Mw and multi-angle sensors) rest on PHOSITA knowledge, not on an express reference disclosure. Expect the patentee to argue the cited record lacks any SLS/MALS teaching and that the asserted combination is hindsight.
3. Claim 1's "bisecting the length of the flow cell" is a construction risk. A narrow reading (a sidewall running along the longitudinal axis) would not read on Wyatt/Larkin's transverse partition. Counter: the patent's own specification and parenthetical (25) ("right triangular cross section spanning a length of the flow cell") tie the phrase to exactly the Wyatt/Larkin geometry — a strong prosecution-history/claim-construction point for the challenger, but one that must be litigated before the merits.
4. "Scattered by the first chamber sidewall" is a §112 problem for the patentee, not a defense. If read literally (true scattering at the internal wall), claim 3/20 may lack written-description support because the specification describes deviation, not scattering, at that wall. Deploy as a parallel §112 attack.
5. The §103 motivation is strongest for claim 19 (method) and weakest for claim 1 (apparatus). For claim 1 the combination rationale is "Anton Paar says integrate RI + size in one instrument, and Wyatt/Larkin is the obvious compact flow-through RI cell." That is a KSR "predictable use of prior-art elements according to their established functions," but it is a step removed from Anton Paar's own express teaching.
6. No secondary-considerations record is available to me. I found no litigation, no PTAB proceeding, and no assertion of US 11,385,154 (reported earlier in this analysis as a negative search result, not a certified nullity). Consequently there is no objective indicia (licensing, commercial success, copying, praise, unexpected results) in the record to weigh either way, and no evidence of the patentee's own non-obviousness narrative beyond the specification.

9. Bottom line

• Claim 1 would have been obvious over Wyatt/Larkin US 6,975,392 B2 in view of Anton Paar EP 3,023,770 A1 / US 10,352,841 B2, because the only element Wyatt/Larkin lacks — a scattered-light sensor for particle-size determination — is precisely what Anton Paar adds, and Anton Paar expressly motivates integrating RI determination into the same scattering instrument to measure both properties on the same sample under the same conditions, with the RI being a required input to the size calculation.
• Claim 18 would have been obvious over that combination further in view of Nakagawa US 2003/0096199 A1 and the LITHIUS NPL (and motivated by the Patterson/McCoy $550M bad-resist NPL).
• Claims 19–20 follow as the inherent method of the combined apparatus, with claim 20 met by Wyatt/Larkin and/or Polymer Characterization WO 2020/078574 A1.
• Claims 3, 11–17, 20 are the most vulnerable and approach §102 over Wyatt/Larkin (fused-silica/45°-partition/RI-deflection/concentration-from-Δn disclosures) combined with Polymer Characterization or Shimadzu on the angle-selection rationale.
• Claims 6–9 are the least vulnerable on the cited record and would require PHOSITA-knowledge/§112 theories in addition to the express references.

Caveat on my own confidence: I verified the content of the primary references (Wyatt/Larkin; Anton Paar; Polymer Characterization; Shimadzu) directly from Google Patents, FPO, EPO Global Patent Index, and Justia. I could not retrieve the full text of the Marquette adapter patent, Canon US 4,715,708 A, Showa Denko US 7,724,356 B2, or Nakagawa US 2003/0096199 A1 before my search budget was exhausted; my characterizations of those four are based on their titles, abstracts, and classification data, and should be confirmed against the full documents before being relied on in any filing.