Case Overview
Shoals Technologies Group, LLC v. Voltage, LLC and Ningbo Voltage Smart Production Co., No. 1:25-cv-00026 (M.D.N.C. June 5, 2026). Memorandum Opinion by Senior United States District Judge Michael F. Urbanski following a bench trial on equitable defenses.
Download the full opinion (PDF)
Background
Shoals Technologies Group, a maker of solar panel lead assembly products, sued Voltage for patent infringement of three utility patents—U.S. Patent Nos. 12,015,375 (the ‘375 patent), 12,015,376 (the ‘376 patent), and 12,407,295 (the ‘295 patent)—alleging that Voltage’s LYNX Trunk Bus product infringes Shoals’s patented lead assembly technology for connecting solar panel arrays to power inverters.
Both parties were simultaneously involved in litigation before the U.S. International Trade Commission (ITC) in Investigation No. 337-TA-1365 involving the same technology. A Prosecution Bar Stipulation was entered in the ITC proceeding on September 20, 2023, requiring Shoals’s law firm, Maschoff Brennan, to erect an ethical wall barring attorneys with access to Voltage’s confidential business information (CBI) from involvement in prosecuting related patent applications before the USPTO.
Voltage sought to have all three patents declared unenforceable, arguing that Shoals’s litigation counsel, Eric Maschoff, violated the Prosecution Bar Stipulation by communicating with patent prosecution attorney Paul Johnson on multiple occasions after the stipulation was entered—in October 2023, February 2024, and December 2024. Voltage contended these communications constituted inequitable conduct before the USPTO and unclean hands warranting unenforceability.
Holding
The court denied Voltage’s motion to declare the patents unenforceable. Voltage’s affirmative defenses of inequitable conduct and unclean hands seeking the remedy of unenforceability were overruled. The patents remain enforceable.
However, the court took under advisement until trial the impact of the acceleration of patent prosecution resulting from Eric Maschoff’s February 21, 2024, violation of the Prosecution Bar Stipulation on any damages that may be awarded in the case.
Key Reasoning
Inequitable Conduct Defense Fails
To prevail on inequitable conduct under Therasense, Inc. v. Becton, Dickinson & Co., 649 F.3d 1276 (Fed. Cir. 2011), the accused infringer must prove by clear and convincing evidence that the applicant misrepresented or omitted material information with the specific intent to deceive the USPTO. The court found that Voltage presented no evidence that Shoals or its patent counsel acted with the specific intent to deceive the USPTO. The defense failed outright.
Unclean Hands Defense Fails
Voltage’s unclean hands argument centered on three sets of claim language in the Shoals patents—“mold,” “drop line cable,” and “extending at least partially through”—that Voltage contended were derived from improper disclosure of its CBI. The court analyzed each category and found:
- Mold terms (October–November 2023 amendments): Voltage offered only conjecture that the amendments replacing “undermold” with “mold” came from use of its CBI. Paul Johnson’s detailed, independent review of publicly available ITC documents—not his fleeting communications with Maschoff—drove the changes.
- Drop line cable and “at least partially through” language (February 2024): While Maschoff’s February 21, 2024, emails and conversation with Johnson violated the broad scope of the Prosecution Bar Stipulation, Paul Johnson spent the bulk of his 6.9 billed hours that day independently reviewing the publicly available Markman order from the 1365 Investigation. The court credited Johnson’s testimony that his amendments stemmed from his own independent analysis.
- December 2024 emails: Paul Johnson credibly testified he only briefly looked at one chart Maschoff sent about the ‘375 patent and deleted the other email about the ‘376 patent without opening the attachment. No clear and convincing evidence established any use of those materials.
Distinguishing Gilead Sciences, Inc. v. Merck & Co., Inc., 888 F.3d 1231 (Fed. Cir. 2018)—where the Federal Circuit affirmed unclean hands based on a totality of misconduct including an attorney who personally continued prosecution after learning confidential information in violation of a firewall—the court found the facts here “starkly different.” Unlike in Gilead, Maschoff transferred prosecution before the Prosecution Bar Stipulation was filed, did not personally continue prosecuting the patents, and did not share any Voltage CBI with Johnson. The misconduct here amounted to “heads up” notifications about public docket developments and suggestions based on publicly available documents.
The court also noted the ITC Administrative Law Judge in the parallel 1438 Investigation reached the same conclusion in a comprehensive 44-page analysis: Voltage did not prove unclean hands.
Equitable Remedy: Damages Adjustment
Although the patents remain enforceable, the court found that Eric Maschoff’s February 21, 2024, communications did violate the Prosecution Bar Stipulation and “accelerated the prosecution of these claims.” The court held that if Shoals obtains a damages award, equity requires the court to account for this acceleration in fashioning the appropriate remedy—potentially adjusting the damages period for the ‘375 and ‘376 patents.
Significance
This 65-page opinion provides a detailed analysis of prosecution bar stipulations in parallel ITC and district court patent litigation. It illustrates the high bar for proving inequitable conduct and unclean hands sufficient to render patents unenforceable, particularly where the alleged misconduct involves communications based on publicly available documents rather than actual disclosure of confidential business information. The court’s approach of finding a stipulation violation but declining the “atomic bomb” remedy of unenforceability—while reserving a more tailored equitable remedy on damages—offers a middle-ground approach that may guide future cases involving prosecution bar disputes.
Case: Shoals Technologies Group, LLC v. Voltage, LLC et al, No. 1:25-cv-00026 (M.D.N.C.)
Judge: Michael F. Urbanski, Senior United States District Judge
Decision Date: June 5, 2026
Document: ECF No. 548 (65 pages)
Patents at Issue: U.S. Patent Nos. 12,015,375; 12,015,376; 12,407,295
GovInfo: USCOURTS-ncmd-1_25-cv-00026