Sionyx, LLC v. Hamamatsu Corporation

I'll research this case across the docket, the Federal Circuit opinion, and the underlying district court litigation.

Case overview and background

A framing note first, because the metadata is easy to misread. Federal Circuit No. 2018‑2019, SiOnyx, LLC v. Hamamatsu Corporation, was not the infringement appeal — it was SiOnyx's appeal of the PTAB's final written decision in IPR2016‑01910 on U.S. Patent 8,680,591, and it was resolved by a nonprecedential, one-page Rule 36 judgment ("AFFIRMED. See Fed. Cir. R. 36," per curiam, Dyk, Clevenger, O'Malley; entered April 3, 2019). The underlying infringement action was SiOnyx, LLC and President and Fellows of Harvard College v. Hamamatsu Photonics K.K., Hamamatsu Corp., Ocean Optics, Inc., No. 1:15‑cv‑13488‑FDS (D. Mass.), filed October 1, 2015 before Judge F. Dennis Saylor IV in Boston; its appeal was separately docketed as Fed. Cir. 19‑2359 and decided December 7, 2020 (SiOnyx, LLC v. Hamamatsu Photonics K.K., 981 F.3d 1339).

The parties and the technology. SiOnyx, LLC (Beverly, MA) is an operating company, not an NPE — founded in 2006 by Harvard professor Eric Mazur and his former student Dr. James Carey to commercialize laser‑textured "black silicon" photodetectors and, later, short‑wave‑infrared/night‑vision cameras. Harvard is the assignee of the Mazur/Carey patents and SiOnyx their exclusive licensee (since a Feb. 10, 2006 license), so the plaintiff side is an operating company plus a university, a configuration that cuts against the classic PAE narrative. Defendants were Hamamatsu Photonics K.K. ("HPK"), the Japanese optoelectronics manufacturer of photomultiplier tubes, photodiodes and image sensors; Hamamatsu Corporation ("HC"), its Bridgewater, NJ marketing/sales subsidiary for North America (HC is the entity named in the IPR and in the Federal Circuit 2018‑2019 caption); and Ocean Optics, Inc. (FL), a downstream spectrometer maker. The accused instrumentalities were HPK's laser‑processed, back‑illuminated near‑IR‑enhanced silicon detectors — principally the S11499 and S11510 series FFT‑CCD image sensors (plus accused avalanche photodiodes and CCDs) — and, as an end product, Ocean Optics' Maya2000 Pro‑NIR spectrometer incorporating the S11510. The commercial dispute was not abstract: SiOnyx alleged Hamamatsu's NIR‑enhanced sensors were direct competitors to its own products.

Patents and posture. Three patents were asserted, each with a different fate. U.S. 8,080,467 (Harvard; Mazur and Carey) claims a method of fabricating a semiconductor wafer by irradiating a silicon substrate surface with temporally short laser pulses to create the black‑silicon texture — this was the patent actually tried to verdict, where the jury found willful infringement on May 9, 2019. U.S. 7,884,446 (Harvard; undulating sub‑micron surface topography) was stipulated out (ECF 422) after its claims were cancelled in an IPR. U.S. 8,680,591 (SiOnyx; Haddad et al., "Photosensitive Imaging Devices and Associated Methods") claims a backside‑illuminated imager with a laser‑textured region on the surface opposite a substantially planar surface bearing the integrated circuitry, plus an electrical transfer element — it survived summary‑judgment practice (Judge Saylor's Aug. 30, 2018 opinion, 330 F. Supp. 3d 574, addressed noninfringement of the '591 and § 315(e)(2) IPR estoppel post‑SAS) but was not among the patents reduced to judgment, and SiOnyx was barred from re‑inserting claim 26 after dropping it (ECF 459, Apr. 27, 2018). In parallel, Hamamatsu's IPR2016‑01910 (filed Sept. 30, 2016; instituted Mar. 30, 2017; FWD Mar. 28, 2018, panel Ullagaddi, Braden, Clements) held claims 1, 2, 4‑11, 13‑18, 21, 23‑25 of the '591 unpatentable over Nakashiba and Mabuchi/Mazur combinations, sustaining only claims 12 and 26 — the ruling affirmed in the 2018‑2019 appeal at issue here. The district court case nonetheless ended in a broad win for SiOnyx: breach of the 2007 NDA by HPK ($796,469 plus pre‑judgment interest), unjust enrichment by HC ($580,640 plus interest), a declaration that Carey is a co‑inventor of nine HPK patents, transfer of ownership of those nine U.S. patents to SiOnyx, and a permanent injunction (Final Judgment, ECF 804, July 26, 2019; amended ECF 834, Sept. 24, 2019). Judge Saylor declined enhanced damages under § 284 (the jury awarded $0 for infringement) and denied § 285 fees.

Why it matters. Three things make this case a staple of practice commentary. First, it is a contract‑law route to patent ownership: the Federal Circuit (19‑2359) held that an NDA clause assigning ownership of all patent rights "in, or arising from" disclosed confidential information can vest sole ownership in the discloser even though the recipient's employees were joint inventors — because inventorship and ownership are distinct, and the parties' agreement controls (a point picked up in academic and firm commentary, and in the court's reliance on Israel Bio‑Engineering v. Amgen). That is a significant caution for any company doing joint development under an NDA. Second, it is a mixed PTAB/litigation outcome: Hamamatsu's IPRs gutted most of the '591 and all of the '446, yet SiOnyx won on the '467 and, more importantly, took Hamamatsu's own U.S. laser‑textured‑photodiode patent family. Third, the district court's 2018 estoppel ruling is frequently cited in post‑SAS § 315(e)(2) debates over "could have raised" grounds, product‑as‑prior‑art, and estoppel against co‑defendants not named as RPI/privies.

Sourcing caveats: the '467 and '446 patent titles and the specific IPR number that cancelled the '446 claims (apparently IPR2016‑01143, Hamamatsu Corp. v. Harvard, cited in SiOnyx's '591 preliminary response) are not fully verified from the materials I could retrieve, and I did not confirm district‑court trial counsel beyond SiOnyx's Pepper Hamilton team (William D. Belanger, Gwendolyn Tawresey) and Hamamatsu's Federal Circuit counsel (John David Simmons, Keith Aaron Jones, Stephen Emerson Murray of Panitch Schwarze Belisario & Nadel).

I'll research this case across the district court, PTAB, and Federal Circuit records.

Now let me dig into the district court docket, Markman order, and PTAB/parallel proceedings.

Let me pull the CourtListener docket and check the early motions (personal jurisdiction, preliminary injunction).

SiOnyx, LLC v. Hamamatsu Photonics K.K. — Chronology of Key Developments

One threshold clarification about "the case." The metadata for this file describes Federal Circuit No. 2018‑2019, which is only the appeal from the PTAB's Final Written Decision in IPR2016‑01910 on U.S. 8,680,591 — a Rule 36 summary affirmance entered 2019‑04‑03. The underlying infringement litigation was SiOnyx, LLC v. Hamamatsu Photonics K.K., No. 1:15‑cv‑13488‑FDS (D. Mass.) (Judge F. Dennis Saylor IV), which went to a jury verdict in May 2019 and produced a second, substantive Federal Circuit appeal, No. 19‑2359 (981 F.3d 1339, decided 2020‑12‑07). Because you asked about the litigation as a whole, I cover all three tracks and flag where they diverge.

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1. Filing and initial pleadings

I'll research the counsel of record for SiOnyx in the Federal Circuit appeal (No. 2018‑2019) and cross-check the underlying IPR and district court appearances.

The Rule 36 judgment gives me the arguing and co-counsel. Now let me verify the full appearance list on the Federal Circuit docket and the attorneys' backgrounds.

Let me pull the Federal Circuit docket itself and the appellant's brief caption, plus verify Belanger's background.

Counsel of record for the plaintiff(s) — Fed. Cir. No. 2018‑2019 (SiOnyx, LLC v. Hamamatsu Corp.)

Framing correction before the names. As noted in the existing case summary, No. 2018‑2019 was not an infringement appeal; it was SiOnyx's appeal of the PTAB's final written decision in IPR2016‑01910 (U.S. 8,680,591), so "plaintiff's counsel" here means counsel for Appellant / Patent Owner SiOnyx, LLC. There was no separate local counsel and no in‑house counsel of record — the Federal Circuit does not require local admission, and I found no SiOnyx legal‑department attorney entering an appearance. The authoritative record of who appeared is the April 3, 2019 Rule 36 judgment, which names exactly two appellant‑side attorneys.

Appellate counsel (No. 2018‑2019)

Source: SiOnyx LLC v. Hamamatsu Corp., No. 2018‑2019 (Fed. Cir. Apr. 3, 2019) (Rule 36 judgment) — "WILLIAM D. BELANGER, Pepper Hamilton LLP, Boston, MA, argued for appellant. Also represented by GWENDOLYN TAWRESEY." https://cases.justia.com/federal/appellate-courts/cafc/18-2019/18-2019-2019-04-03.pdf

Related plaintiff-side teams you may need to cross-reference (same litigation family, different dockets)

• PTAB, IPR2016‑01910 (patent owner SiOnyx): lead counsel Thomas J. Engellenner (Reg. No. 28,711) and back‑up Reza Mollaaghababa, both Pepper Hamilton LLP, Boston — per SiOnyx's mandatory notices/powers of attorney filed in the Hamamatsu IPRs (e.g., IPR2017‑00909, Mar. 1, 2017), which also list the service address 125 High Street, 19th Floor, Boston, MA 02110 and the dedicated address SiOnyx_IPR@pepperlaw.com.
• D. Mass. No. 1:15‑cv‑13488‑FDS (the infringement/contract case; plaintiffs SiOnyx + Harvard): William Belanger (Mass. BBO 657184), Miranda Hooker, Anthony H. Cataldo, and Gwendolyn Tawresey (Mass. BBO 692887), all Pepper Hamilton LLP, per the plaintiffs' Notice of Appeal signed Oct. 24, 2019 (appealing ECF 804/834). Cataldo also entered an appearance as of counsel in Fed. Cir. No. 19‑2359 (Dkt. 18, Dec. 20, 2019); Belanger filed as principal counsel and Tawresey as of counsel in that appeal (Dkts. 14–15, 27–28).
• Fed. Cir. No. 19‑2359/20‑1217 (the 2020 merits appeal): Belanger (principal, argued Oct. 6, 2020) and Tawresey (of counsel), with Maia H. Harris also listed on the rehearing‑response papers.

Sourcing caveats (please read before publishing)

1. I could not retrieve the actual 2018‑2019 Federal Circuit docket sheet. Free/aggregator coverage of the 2018‑2019 docket (as opposed to 19‑2359, whose docket I did retrieve in full via a Patexia mirror) was not available to me. The Rule 36 judgment is therefore my authoritative source for who appeared and argued; I could not independently confirm whether Thomas Engellenner, Reza Mollaaghababa, Anthony Cataldo, or Miranda Hooker also filed entries of appearance in 2018‑2019. Given the IPR team structure, Engellenner is a plausible additional of‑counsel appearance, but I am not asserting it.
2. No in‑house counsel identified. SiOnyx's corporate parent is CF Sion, LLC (per the PTAB mandatory notices); no SiOnyx in‑house attorney appears in any public filing I located.
3. Firm name is time‑sensitive. At the time of the appeal the firm was Pepper Hamilton LLP (as the judgment itself states); Pepper Hamilton combined with Troutman Sanders on January 1, 2021 to form Troutman Pepper Hamilton Sanders LLP, and the firm rebranded as Troutman Pepper Locke in 2025. Bios and contact details at troutman.com reflect the current entity.
4. Role labels. The Federal Circuit does not use "lead counsel" formally; Belanger was designated principal counsel in the firm's Federal Circuit entries of appearance in the companion appeal (Dkt. 27), which is my basis for labeling him lead. Tawresey's "of counsel" designation tracks Dkt. 28 in 19‑2359 and the "also represented by" formulation in the 2018‑2019 judgment.
5. I did not find any Law360 or Reuters Legal piece specifically listing the 2018‑2019 appellate team beyond the judgment; the names above are grounded in court filings, not press reports.

I'll research counsel of record for the Hamamatsu defendants across the IPR, the Federal Circuit appeal, and the underlying district court case.

Counsel of record for the Hamamatsu defendants

Verification status up front. Everything below comes from three independent, retrievable sources: (1) the Federal Circuit's April 3, 2019 Rule 36 disposition in No. 2018‑2019, which recites the arguing and non‑arguing counsel of record; (2) the defendants' own signature and service blocks in the D. Mass. filings; and (3) Panitch Schwarze's § 42.10(b) power of attorney filed with the Board. Where I could not confirm something, I say so. Two structural points matter before the names:

• In this appeal (2018‑2019), the only appellee was Hamamatsu Corporation (HC) — HPK and Ocean Optics were not parties to IPR2016‑01910 and therefore had no counsel of record in the Federal Circuit appeal.
• In the underlying district court case, all three entities (HPK, HC, Ocean Optics) were represented by the same defense team. Judge Saylor expressly noted that Ocean Optics "shares counsel with HPK and HC" — a fact that mattered to his § 315(e)(2) estoppel analysis (330 F. Supp. 3d 574).

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1. Federal Circuit No. 2018‑2019 (appellee Hamamatsu Corporation)

The Rule 36 disposition states: "JOHN DAVID SIMMONS, Panitch Schwarze Belisario & Nadel LLP, Philadelphia, PA, argued for appellee. Also represented by KEITH AARON JONES, STEPHEN EMERSON MURRAY."

Note on the panel: Dyk, Clevenger, O'Malley (per curiam). The disposition recites argument, so the case was argued before the Rule 36 affirmance — I did not independently verify the argument date.

2. PTAB — IPR2016‑01910 (Hamamatsu Corp. v. SiOnyx, LLC)

Hamamatsu's power of attorney designates the attorneys associated with Customer No. 000570 — Panitch Schwarze Belisario & Nadel LLP — with the identical three‑lawyer lineup:

• Lead: John D. Simmons (Reg. No. 52,225), jsimmons@panitchlaw.com, (215) 965‑1268
• Back‑up: Stephen E. Murray (Reg. No. 63,206); Keith A. Jones (Reg. No. 67,781)

Caveat: the executed POA I retrieved is the one filed in the companion '467 proceeding, IPR2017‑00909 (Hamamatsu Corp. v. President & Fellows of Harvard College, Feb. 14, 2017). Same petitioner, same customer number, same three attorneys, and the IPR2016‑01910 petition caption carries the same Panitch Schwarze attribution — but I did not pull the IPR2016‑01910 POA itself, so treat the IPR‑specific appointment as inferred rather than directly verified.

3. D. Mass. No. 1:15‑cv‑13488‑FDS (all defendants: HPK, HC, Ocean Optics)

The defense signature/service block used on filings through judgment and appeal (e.g., the Oct. 24, 2019 notice of appeal's certificate of service) lists:

Ocean Optics, Inc.: no separate firm appears. Consistent with Judge Saylor's observation that Ocean Optics "shares counsel with HPK and HC," it was covered by the Panitch Schwarze team (plus local counsel) rather than retaining independent counsel — which is also why the court treated all defendants together for the § 315(e)(2) estoppel analysis.

4. Subsequent appeal, Fed. Cir. 19‑2359 (for continuity)

The appellants there were HPK and HC (Ocean Optics did not appeal). The Federal Circuit attorney listing for that appeal shows Panitch Schwarze Belisario & Nadel LLP (Simmons, Murray, Jones) together with Minamino Law Office PLLC (Koichiro Minamino) — i.e., the same defense team, carried forward. The January 6, 2021 rehearing petition is signed "/s/ John D. Simmons … Counsel for Defendants‑Appellants."

5. In‑house counsel

I found no Hamamatsu or Ocean Optics in‑house attorney appearing of record in the PTAB, district court, or Federal Circuit dockets. The PTAB power of attorney was executed by an authorized Hamamatsu signatory (unnamed in the copy I retrieved), which is the only in‑house involvement visible. I would not state a name for any in‑house lawyer without pulling the POA signature page or the D. Mass. appearance forms.

6. Gaps and caveats

• I did not retrieve the raw PACER docket sheet for 1:15‑cv‑13488 or the Fed. Cir. 2018‑2019 docket. Additional per‑firm appearances (e.g., other Panitch associates who entered and withdrew, or an earlier Boston local‑counsel firm before Callanan Law) may exist on the docket and are not captured here. Everything above is drawn from signed filings and the court's own counsel recitations, which are reliable but not exhaustive of the docket.
• No sealed‑counsel issue is apparent: the defense team was disclosed in public filings throughout.
• No contradiction with the prior sections. The earlier summary's statement that Hamamatsu's Federal Circuit counsel were "John David Simmons, Keith Aaron Jones, Stephen Emerson Murray of Panitch Schwarze Belisario & Nadel" is confirmed by the Rule 36 disposition itself; the previous caveat that this was unverified can now be removed. The only refinement worth flagging is the scope point: Simmons/Jones/Murray appeared for Hamamatsu Corporation alone in 2018‑2019 (HC was the sole IPR petitioner/appellee), while in the district court the same team — plus Callanan as local counsel and Minamino as Japan‑side counsel — represented all three defendants, including Ocean Optics.