Force MOS v. ASUSTeK: $10.5M MOSFET Patent Verdict After 926-Day Trial
Force MOS Technology sued ASUSTeK Computer in the Eastern District of Texas, asserting two trench MOSFET patents covering advanced power semiconductor architectures. After 926 days of litigation, a jury found willful infringement and awarded $10,500,000 as a lump-sum reasonable royalty — the single number that defines this case’s commercial significance.
Trench MOSFET showdown: Force MOS extracts $10.5M from ASUSTeK
Force MOS Technology Co., Ltd., a power semiconductor IP holder, filed suit against ASUSTeK Computer, Inc. in the Eastern District of Texas on 28 November 2022, asserting infringement of two issued U.S. patents: US7847346B2, covering a trench MOSFET with trench source contact configured for copper wire bonding, and US7629634B2, covering a trenched MOSFET with trenched source contact. The case was assigned to Judge Rodney Gilstrap, one of the most experienced patent trial judges in the country.
After 926 days of litigation, the case concluded on 11 June 2025 with a jury verdict fully in Force MOS’s favour. The jury found that ASUSTeK infringed Claims 1, 2, and 3 of the ‘634 Patent and Claim 1 of the ‘409 Patent, and rejected ASUSTeK’s invalidity challenge to Claim 1 of the ‘409 Patent. The jury also found ASUSTeK’s infringement to be willful. Damages were set at $10,500,000 as a lump-sum reasonable royalty. Judge Gilstrap declined to enhance the award despite the willfulness finding, concluding that the conduct did not rise to the level of egregious culpable behaviour warranting enhancement under 35 U.S.C. § 284.
The 926-day duration reflects a case that ran through full Markman proceedings, likely summary judgment motions, and ultimately a jury trial — consistent with the intensive litigation load typical of E.D. Texas. The court’s decision not to enhance despite willfulness is notable: it signals that willfulness alone does not guarantee multiplied damages, and that Judge Gilstrap applied a rigorous ‘totality of circumstances’ standard. Pre-judgment interest at the 5-year Treasury Bill rate compounded quarterly and post-judgment interest at the statutory rate were also awarded, meaningfully increasing ASUSTeK’s total exposure beyond the headline $10.5M figure.
Filing to Judgment on the merits for Plaintiff in 926 days
926 days — above the median for E.D. Texas patent cases, reflecting a full trial on the merits
Jury verdict for Force MOS: what the $10.5M award means for both parties
Lump-sum royalty: how $10.5M was structured
The jury awarded damages as a lump-sum reasonable royalty rather than a running per-unit rate. A lump sum resolves all past and — depending on the judgment’s scope — potentially future infringement exposure in a single payment. It also avoids the complexity of ongoing royalty accounting. The $10.5M figure represents the jury’s assessment of what a hypothetical negotiation between the parties would have yielded at the time infringement began.
Lump-sum reasonable royaltyForce MOS: patents validated, royalty secured, costs awarded
Force MOS emerged with full vindication: both asserted patents survived invalidity challenge, three claims were found infringed across two patents, and the jury’s willfulness finding — even without enhancement — strengthens Force MOS’s posture in any downstream licensing negotiations. Recovery of costs as prevailing party adds further financial weight. The pre- and post-judgment interest awards meaningfully increase ASUSTeK’s effective payment obligation beyond the base $10.5M.
Full plaintiff verdictASUSTeK: willfulness found, invalidity defence rejected
ASUSTeK faces a $10.5M lump-sum payment plus costs, pre-judgment interest from the date of infringement, and post-judgment interest until paid — making the true financial burden materially higher than the headline royalty. The jury rejected its invalidity defence for the ‘409 Patent’s Claim 1. The willfulness finding, while not resulting in enhanced damages here, may complicate any appeal and could influence future licensing discussions with Force MOS or related parties.
Full defendant loss at trialMOSFET IP: a validated enforcement signal for power semiconductor patents
This verdict confirms that trench MOSFET architecture patents can sustain jury trial scrutiny and command eight-figure royalty awards against major electronics manufacturers. Power semiconductor IP holders — particularly those with patents on trench contact structures — should view this outcome as a benchmark. Companies designing or sourcing trench MOSFET components for PC or consumer electronics products should prioritise FTO clearance against US7847346B2 and US7629634B2 and related family members.
Power semiconductor IP riskFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Force Mos Technology Co., Ltd. | Company | Power semiconductor IP licensor — holder of US7847346B2 and US7629634B2Search in Eureka ↗ |
| Defendant | Asustek Computer, Inc. | Company | ASUSTeK Computer, Inc. — global PC and electronics manufacturer accused of MOSFET patent infringementSearch in Eureka ↗ |
| Plaintiff counsel | Ariana Deskins Pellegrino | Attorney | Counsel for Force Mos Technology Co., Ltd.Search in Eureka ↗ |
| Plaintiff counsel | Bryan Donivan Atkinson | Attorney | Counsel for Force Mos Technology Co., Ltd.Search in Eureka ↗ |
| Plaintiff counsel | Christopher Edward Hanba | Attorney | Counsel for Force Mos Technology Co., Ltd.Search in Eureka ↗ |
| Plaintiff counsel | Jordan Elizabeth Garsson | Attorney | Counsel for Force Mos Technology Co., Ltd.Search in Eureka ↗ |
| Plaintiff counsel | Joshua Gabriel Jones | Attorney | Counsel for Force Mos Technology Co., Ltd.Search in Eureka ↗ |
| Plaintiff counsel | Joshua Reed Thane | Attorney | Counsel for Force Mos Technology Co., Ltd.Search in Eureka ↗ |
| Plaintiff counsel | Michael David Saunders | Attorney | Counsel for Force Mos Technology Co., Ltd.Search in Eureka ↗ |
| Plaintiff counsel | Ross Spencer Garsson | Attorney | Counsel for Force Mos Technology Co., Ltd.Search in Eureka ↗ |
| Plaintiff counsel | Tron Y. Fu | Attorney | Counsel for Force Mos Technology Co., Ltd.Search in Eureka ↗ |
| Plaintiff law firm | Dickinson Wright PLLC | Law Firm | Representing Force Mos Technology Co., Ltd.Search in Eureka ↗ |
| Plaintiff law firm | Dickinson Wright PLLC (Austin) | Law Firm | Representing Force Mos Technology Co., Ltd.Search in Eureka ↗ |
| Plaintiff law firm | Haltom & Doan LLP | Law Firm | Representing Force Mos Technology Co., Ltd.Search in Eureka ↗ |
| Defendant counsel | Andrew Thompson (Tom) Gorham | Attorney | Counsel for Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant counsel | Charles M. McMahon | Attorney | Counsel for Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant counsel | Dorian Ojemen | Attorney | Counsel for Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant counsel | Gregory Proctor | Attorney | Counsel for Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant counsel | James Travis Underwood | Attorney | Counsel for Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant counsel | Kalpesh K. Shah | Attorney | Counsel for Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant counsel | Kathleen Lynch | Attorney | Counsel for Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant counsel | Li Chen | Attorney | Counsel for Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant counsel | Louis Constantinou | Attorney | Counsel for Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant counsel | Mackenzie Marie Martin | Attorney | Counsel for Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant counsel | Melissa Richards Smith | Attorney | Counsel for Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant counsel | Nicholas O. Kennedy | Attorney | Counsel for Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant counsel | Richard Vincent Wells | Attorney | Counsel for Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant counsel | Thomas Michael DaMario | Attorney | Counsel for Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant counsel | Victor Martinez | Attorney | Counsel for Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant counsel | Ziyong Sean Li | Attorney | Counsel for Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant law firm | Baker & McKenzie LLP | Law Firm | Representing Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant law firm | Baker & McKenzie LLP (Dallas) | Law Firm | Representing Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant law firm | Baker & McKenzie LLP – Washington | Law Firm | Representing Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant law firm | Benesch, Friedlander, Coplan & Aronoff LLP | Law Firm | Representing Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant law firm | Benesch, Friedlander, Coplan & Aronoff LLP (Chicago) | Law Firm | Representing Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant law firm | Gillam & Smith LLP | Law Firm | Representing Asustek Computer, Inc.Search in Eureka ↗ |
| Defendant law firm | Lumens Law Group PLLC | Law Firm | Representing Asustek Computer, Inc.Search in Eureka ↗ |
| Presiding judge | Judge Rodney Gilstrap | Judge | Texas Eastern District CourtSearch in Eureka ↗ |
Official order — verbatim text
The final judgment covers four distinct legal conclusions: patent ownership (standing confirmed), infringement across multiple claims of both patents, validity of the ‘409 Patent’s Claim 1, and willfulness. The court’s separate decision on enhancement — declining to multiply despite willfulness — reflects the Supreme Court’s Halo Electronics standard requiring ‘egregious’ conduct. The prejudgment interest award at the 5-year Treasury rate compounded quarterly signals that Force MOS’s total recovery will meaningfully exceed the $10.5M base. ASUSTeK bears costs as the non-prevailing party.
US7847346B2 & US7629634B2 — Trench MOSFET Power Semiconductor Patents
US7847346B2 (application no. 12/292780) claims a trench MOSFET device incorporating a trench source contact designed to accommodate copper wire bonding — a structural innovation relevant to advanced power packaging. US7629634B2 (application no. 12/036243) claims a trenched MOSFET with a trenched source contact structure. Both patents operate in the power semiconductor domain, specifically addressing device architectures that improve on-resistance and current handling in discrete power transistor applications used in computing and consumer electronics platforms.
For the power semiconductor sector, these patents represent enforcement-validated IP in a technology space with growing commercial salience: trench MOSFET devices are foundational to power management in motherboards, voltage regulators, and DC-DC conversion circuits — precisely the application domain relevant to an electronics manufacturer like ASUSTeK. The jury’s rejection of ASUSTeK’s invalidity challenge to the ‘409 Patent strengthens the enforceability signal for both patents, and the $10.5M royalty verdict establishes a discoverable damages anchor for future licensing or litigation involving these or closely related patent families.
Should you run an FTO against US7847346B2 and US7629634B2?
Any company designing, sourcing, or integrating trench MOSFET components into PC motherboards, power modules, voltage regulator circuits, or consumer electronics platforms should treat this verdict as a direct FTO trigger. ASUSTeK’s loss on both infringement and invalidity — across three claims of the ‘634 Patent and one claim of the ‘409 Patent — confirms that these patents have survived adversarial challenge at the jury trial level. Downstream customers of infringing components may also face exposure depending on supply chain relationships.
PatSnap Eureka’s FTO Search Agent can map your product’s trench MOSFET architecture against the claim scope of US7847346B2 and US7629634B2, identify related family members and continuations, and surface prior art that may not have been presented at trial. For R&D teams evaluating next-generation power transistor designs, early FTO analysis against these patents — and Force MOS’s broader portfolio — is materially lower-cost than litigation exposure of the kind ASUSTeK faced.
Run a freedom-to-operate analysis on US7847346B2 to assess your product’s exposure
Run FTO in Eureka →Similar MOSFET & power semiconductor patent cases in E.D. Texas
Cases involving trench MOSFET and power semiconductor patents litigated in the Eastern District of Texas before Judge Gilstrap and peers.
Related patent case — similar technology
Comparable case in the same technology domain. Patent holder and defendant reached resolution after proceedings.
SettledRelated infringement action — same court
Comparable Trench MOSFET with trench source contact having copper wire bonding-adjacent infringement action. Patent enforcement dynamics analysed in depth.
Active · District CourtRelated invalidity challenge — appellate outcome
Combined invalidity and infringement action in the same technology space. Decided after substantive proceedings.
DecidedForce Mos Technology Co., Ltd.’s broader IP enforcement history
Force Mos Technology Co., Ltd.’s full litigation history covering prior enforcement, licensing activity, and inter partes review proceedings.
Portfolio viewWhat this verdict signals for the power semiconductor IP landscape
A $10.5M jury verdict with willfulness and sustained patent validity reshapes enforcement calculus for MOSFET-adjacent IP portfolios.
Willfulness without enhancement is still a powerful litigation outcome
Judge Gilstrap’s refusal to enhance despite willfulness reinforces that § 284 enhancement requires egregious conduct — not merely deliberate infringement. For patent holders, willfulness findings remain strategically valuable in licensing leverage even when courts decline to multiply damages. Defendants should not assume willfulness automatically doubles or trebles exposure.
Pre-judgment interest compounds the real cost of infringement well beyond the jury award
With interest calculated at the 5-year Treasury Bill rate compounded quarterly from the date of infringement, ASUSTeK’s effective liability substantially exceeds $10.5M. Companies facing patent assertions in long-running E.D. Texas cases should model interest accrual from earliest alleged infringement dates — not just the verdict figure — when evaluating settlement economics.
Force MOS’s acquisition of the ‘409 Patent was a jury-validated IP transfer
The jury explicitly found that Force MOS acquired all rights to the ‘409 Patent from inventor Dr. Fu-Yuan Hshieh, clearing a potential standing and assignment challenge. This is a notable data point for IP acquisition strategies: thorough chain-of-title documentation can survive adversarial jury scrutiny and underpin an eight-figure damages award.
E.D. Texas MOSFET verdicts set royalty benchmarks for the broader power IC sector
A $10.5M lump-sum across two patents and multiple claims sets a discoverable royalty benchmark. Competitors and licensees in the trench MOSFET and power MOSFET space — including gate driver IC makers and module integrators — should expect this verdict to anchor future licensing demands and litigation damages models involving similar semiconductor architecture patents.
Force v Asustek — key questions answered
The jury found that ASUSTeK infringed Claims 1, 2, and 3 of US7629634B2 and Claim 1 of US7847346B2, that Claim 1 of the ‘409 Patent is not invalid, and that infringement was willful. Damages were set at $10,500,000 as a lump-sum reasonable royalty. The court declined to enhance despite willfulness.
Judge Gilstrap applied the Supreme Court’s Halo Electronics standard, under which enhancement under 35 U.S.C. § 284 is ‘generally reserved for egregious cases of culpable behavior.’ Having presided over the full trial, he concluded that the totality of circumstances did not warrant enhancement, even though the jury found willfulness.
Force MOS asserted US7847346B2 (application 12/292780), covering a trench MOSFET with trench source contact for copper wire bonding, and US7629634B2 (application 12/036243), covering a trenched MOSFET with trenched source contact. Both are power semiconductor patents in the trench MOSFET architecture space.
The accused products related to trench MOSFET components with trench source contact structures incorporating copper wire bonding — power transistor architectures used in computing and consumer electronics platforms consistent with ASUSTeK’s motherboard and PC product lines.
The jury explicitly found that Force MOS acquired all rights to US7847346B2 from inventor Dr. Fu-Yuan Hshieh. This resolved a potential standing and chain-of-title challenge that could have barred Force MOS’s claims. The finding confirms that the patent assignment was legally effective and that Force MOS had standing to assert the patent throughout the litigation.
Monitor MOSFET patent enforcement before it reaches litigation
Use PatSnap Eureka to run FTO searches against US7847346B2 and US7629634B2 and track Force MOS’s patent portfolio for new filings and enforcement signals. Early clearance analysis costs a fraction of the $10.5M exposure ASUSTeK faced at verdict.
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