Purdue University v. STMicroelectronics: $32.5M SiC MOSFET Patent Verdict
The Trustees of Purdue University secured a unanimous jury verdict against STMicroelectronics International N.V. and STMicroelectronics, Inc. for infringing claims 9 and 10 of US7,498,633, covering silicon carbide MOSFET technology. The court awarded $32.5 million in compensatory damages, with ST’s SiC MOSFET product line — spanning over 90 SKUs — found to directly and inductively infringe the asserted patent.
Purdue’s SiC power patent survives ST’s full validity challenge
Filed in July 2021 before Judge Alan D. Albright in the Western District of Texas, this infringement action pitted Purdue University — holder of foundational silicon carbide MOSFET patents — against STMicroelectronics, one of the world’s largest semiconductor manufacturers. The asserted patent, US7,498,633, covers SiC MOSFET device architecture, and ST’s accused products spanned more than 90 STPOWER SiC MOSFET product variants across multiple voltage and current ratings used in power electronics applications including EV inverters and industrial drives.
After a jury trial commencing November 27, 2023, the jury returned a unanimous verdict on December 4, 2023, finding that both ST entities directly infringed and induced infringement of claims 9 and 10 of the ‘633 Patent, and that the challenged claims are not invalid. The court entered final judgment on June 6, 2024, awarding Purdue $32.5 million in compensatory damages through December 31, 2022, plus recoverable costs. Notably, the court granted ST’s Rule 50(a) directed verdict on willful infringement — meaning Purdue cannot seek enhanced damages — but the core infringement and damages award stands.
The 1,058-day duration reflects the substantive complexity of SiC semiconductor litigation, including a bench trial component on inequitable conduct that ST ultimately lost. The public record is silent on whether Purdue pursued or obtained ongoing royalties or pre- and post-judgment interest, as those motions were reserved for post-trial briefing. The outcome signals sustained enforceability of university-held SiC power device patents against major commercial semiconductor players, with significant implications for the rapidly expanding SiC power electronics market.
Filing to Judgment on the merits for Plaintiff in 1058 days
1,058 days from filing to final judgment — nearly 3 years, typical for complex semiconductor patent trials in W.D. Texas
Jury verdict for Purdue: what the $32.5M judgment means for both parties
Jury verdict plus bench trial: a two-track proceeding
This case involved both a jury trial on infringement, validity, and damages, and a separate bench trial on ST’s inequitable conduct defence. The jury found direct and induced infringement of claims 9 and 10 of US7,498,633 and upheld patent validity. The court separately rejected inequitable conduct. ST obtained a directed verdict on willfulness, capping Purdue’s recovery at compensatory damages only — no trebling.
Judgment on the meritsPurdue secures $32.5M and a valid, enforceable patent
Purdue prevails on the core issues: infringement confirmed, patent not invalid, inequitable conduct rejected, and marking compliance established. The $32.5M award covers damages through end of 2022 only, suggesting Purdue retains the right to pursue ongoing royalties or supplemental damages for ST’s post-2022 SiC MOSFET sales — a potentially significant additional sum given the scale of ST’s SiC product portfolio.
Patent upheld and enforcedST faces $32.5M liability with ongoing royalty exposure
STMicroelectronics avoids enhanced damages via the willfulness directed verdict, limiting exposure to single compensatory damages. However, with the patent upheld as valid and enforceable and post-2022 damages not yet adjudicated, ST faces potential additional royalty liability on a product line central to its power semiconductor growth strategy. ST’s appellate options — including CAFC appeal and possible IPR petitions — remain open.
Compensatory damages onlySiC power patent enforcement risk rises for the sector
The verdict reinforces that university-held SiC MOSFET patents carry real enforcement teeth in high-stakes commercial markets. With EV, industrial, and renewable energy applications driving rapid SiC MOSFET adoption, manufacturers building on ST-compatible SiC architectures should treat US7,498,633 as an active freedom-to-operate risk. The ruling may embolden Purdue and other university IP holders to pursue further enforcement across the SiC supply chain.
SiC FTO risk elevatedFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | The Trustees of Purdue University | Individual | Research university IP licensor — holder of US7498633B2 covering SiC MOSFET device architectureSearch in Eureka ↗ |
| Defendant | STMicroelectronics, Inc. | Company | Global semiconductor manufacturer; ST’s SiC MOSFET STPOWER product line found to infringeSearch in Eureka ↗ |
| Co-Defendant | STMicroelectronics International, N.V. | Individual | Search in Eureka ↗ |
| Co-Defendant | STMicroelectronics, Inc. | Company | Search in Eureka ↗ |
| Plaintiff counsel | Abbey E. Mcnaughton | Attorney | Counsel for The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff counsel | Alfonso Garcia Chan | Attorney | Counsel for The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff counsel | Brian D. Melton | Attorney | Counsel for The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff counsel | Chijioke E. Offor | Attorney | Counsel for The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff counsel | Craig D. Cherry | Attorney | Counsel for The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff counsel | Halima Shukri Ndai | Attorney | Counsel for The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff counsel | Hayley Stillwell | Attorney | Counsel for The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff counsel | John P. Lahad | Attorney | Counsel for The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff counsel | Mark D. Siegmund | Attorney | Counsel for The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff counsel | Michael W. Shore | Attorney | Counsel for The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff counsel | Mu Lin Hsu | Attorney | Counsel for The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff counsel | Raphael Denis Philippe Chabaneix | Attorney | Counsel for The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff counsel | Samuel E. Joyner | Attorney | Counsel for The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff law firm | Cherry Johnson Siegmund James PLLC | Law Firm | Representing The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff law firm | Frost, Brown & Todd LLC | Law Firm | Representing The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff law firm | King & Spalding LLP | Law Firm | Representing The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff law firm | McKool Smith PC | Law Firm | Representing The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff law firm | Offor Evans PLLC | Law Firm | Representing The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff law firm | Susman Godfrey LLP | Law Firm | Representing The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Plaintiff law firm | The Shore Firm | Law Firm | Representing The Trustees of Purdue UniversitySearch in Eureka ↗ |
| Defendant counsel | Bruce S. Sostek | Attorney | Counsel for STMicroelectronics, Inc.Search in Eureka ↗ |
| Defendant counsel | Dina W. Mckenney | Attorney | Counsel for STMicroelectronics, Inc.Search in Eureka ↗ |
| Defendant counsel | Justin S. Cohen | Attorney | Counsel for STMicroelectronics, Inc.Search in Eureka ↗ |
| Defendant counsel | Nadia Elena Haghighatian | Attorney | Counsel for STMicroelectronics, Inc.Search in Eureka ↗ |
| Defendant counsel | Richard L. Wynne , Jr. | Attorney | Counsel for STMicroelectronics, Inc.Search in Eureka ↗ |
| Defendant law firm | Holland & Knight LLP | Law Firm | Representing STMicroelectronics, Inc.Search in Eureka ↗ |
| Defendant law firm | Kirkland & Ellis LLP | Law Firm | Representing STMicroelectronics, Inc.Search in Eureka ↗ |
| Presiding judge | Judge Alan D Albright | Judge | Texas Western District CourtSearch in Eureka ↗ |
Official order — verbatim text
The final judgment language is unusually detailed, reflecting a dual-track proceeding. The jury’s unanimous infringement and validity findings on claims 9 and 10 carry full legal weight for damages and injunctive purposes. The court’s separate bench findings rejecting inequitable conduct close one of ST’s strongest affirmative defences. The Rule 50(a) directed verdict on willfulness is significant procedurally — it was granted mid-trial before the jury deliberated, signalling the court found insufficient evidence of subjective bad faith — but it does not disturb the liability or damages findings, and Purdue retains the right to pursue pre- and post-judgment interest and ongoing royalties.
US7498633B2 — Silicon Carbide Power MOSFET Device Architecture
US7,498,633 (application no. US11/338007) protects silicon carbide metal-oxide-semiconductor field-effect transistor (MOSFET) device architecture — specifically the structural and electrical configurations enabling SiC MOSFETs to operate at high voltages and temperatures with low on-resistance. SiC-based power devices represent a step-change over silicon in efficiency and thermal performance, making them foundational to next-generation power conversion systems in electric vehicles, renewable energy inverters, and industrial motor drives. Purdue’s foundational research in SiC power devices dates to early commercialisation of the technology.
With global SiC MOSFET demand accelerating — driven by EV traction inverter adoption and grid infrastructure upgrades — US7,498,633 occupies commercially critical territory. The verdict establishes that ST’s entire STPOWER SiC MOSFET line, spanning discrete, module, and bare-die formats across 65V to 170V classes, falls within claims 9 and 10. This signals that the patent’s claim scope is broad enough to cover mainstream commercial SiC device architectures, elevating FTO risk for every major SiC device manufacturer including Wolfspeed, Infineon, ROHM, and onsemi.
Should your SiC MOSFET product line be cleared against US7498633B2?
Any company designing, manufacturing, or importing SiC power MOSFETs — whether for EV powertrains, solar inverters, industrial drives, or charging infrastructure — should treat US7,498,633 as a live freedom-to-operate risk following this verdict. The court found that over 90 ST product SKUs across multiple voltage classes infringe claims 9 and 10. If your SiC MOSFET architecture shares structural features with mainstream trench-gate or planar body designs, a targeted FTO analysis against these specific claims is now essential, not optional.
PatSnap Eureka’s FTO Search Agent can map your SiC MOSFET device specifications against the asserted claims of US7,498,633 and the broader Purdue SiC portfolio, identifying design-around opportunities and claim overlap risk before your next product tape-out. Eureka also monitors new Purdue patent filings and continuation applications that may extend the enforceability window — giving your IP and R&D teams early warning across the full SiC power semiconductor claim landscape.
Run a freedom-to-operate analysis on US7498633B2 to assess your product’s exposure
Run FTO in Eureka →Similar SiC & power semiconductor patent cases in W.D. Texas
Cases involving SiC MOSFET and power semiconductor patent infringement before Judge Albright and the W.D. Texas district court.
What this case signals for the SiC power semiconductor IP landscape
A $32.5M verdict against a tier-one semiconductor company marks a turning point for SiC MOSFET patent enforcement globally.
University SiC patents are now commercially weaponised
Purdue’s win demonstrates that foundational SiC MOSFET patents held by research institutions can withstand full commercial validity challenges — including inequitable conduct attacks — and generate nine-figure damages at trial. Any SiC power device manufacturer should treat Purdue’s portfolio as an active litigation risk, not an academic footnote.
Willfulness carve-out limits ST’s pain but not the precedent
The directed verdict on willfulness means no treble damages here, but the core infringement and validity findings are binding. Other defendants facing Purdue patent assertions cannot rely on a similar procedural escape unless their design-around efforts or notice timelines differ materially from ST’s record.
University v STMicroelectronics — key questions answered
The jury returned a unanimous verdict on December 4, 2023, finding that STMicroelectronics International N.V. and STMicroelectronics, Inc. directly infringed and induced infringement of claims 9 and 10 of US7,498,633. The challenged claims were found not invalid. The court entered final judgment on June 6, 2024, awarding Purdue $32.5 million in compensatory damages through December 31, 2022.
US7,498,633B2 (application US11/338007), assigned to The Trustees of Purdue University, protects silicon carbide MOSFET device architecture. The patent covers structural configurations of SiC-based power transistors enabling high-voltage, high-temperature switching with low on-resistance — technology foundational to EV inverters, industrial drives, and renewable energy power conversion systems. Claims 9 and 10 were the asserted and infringed claims in this litigation.
On November 28, 2023, mid-trial, Judge Albright granted ST’s oral Rule 50(a) motion for a directed verdict that ST did not willfully infringe the ‘633 Patent. A Rule 50(a) directed verdict is granted when no reasonable jury could find for the non-moving party on the evidence presented. This means Purdue cannot seek enhanced (up to trebled) damages under 35 U.S.C. § 284, though the base $32.5M compensatory award and costs recovery are unaffected.
The judgment covers the STPOWER SiC MOSFET product line — over 90 SKUs spanning voltage ratings from 65V to 170V, including bare-die, discrete TO-package, and multi-chip module formats. Product families include the SCT, SCTH, SCTW, SCTWA, SCTHS, SCTHU, SCTL, SCTL, and SCTYA series. Both direct infringement (by ST) and induced infringement (of downstream customers) were found for claims 9 and 10.
Yes. The final judgment entered June 6, 2024 starts the clock for post-trial motions (including JMOL, new trial motions) and any appeal to the U.S. Court of Appeals for the Federal Circuit. ST may also explore inter partes review petitions at the USPTO challenging the ‘633 Patent claims, though the one-year IPR bar from service of complaint (July 2021) has likely passed, potentially limiting that avenue depending on filing history.
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