SK nexilis v Volta Energy Solutions (CFI, UPC_CFI_706/2025, 23 October 2026)

Dhenne Avocats · 1 November 2026

Our analysis

Summary

In a decision of 23 October 2026 (UPC_CFI_706/2025), the Mannheim Local Division dismissed SK nexilis’ action against three Volta Energy Solutions companies for infringement of EP 3 316 363, which concerns an electrolytic copper foil for a secondary battery. The claimed roughness value is a count of peaks over the measured length, not a value normalised to 1 cm. The counterclaim for revocation, made conditional on a finding of infringement, is not decided, and the claimant bears its costs.

Facts and procedure

SK nexilis, a Korean copper-foil manufacturer, owns EP 3 316 363, in force in France, Germany, Italy, Luxembourg and Sweden. It alleged that Volta Energy Solutions S.à r.l., Volta Energy Solutions Europe Kft. and Volta Energy Solutions Hungary Kft. market foils falling within claim 1, which requires in particular a peak count roughness Rpc of 10 to 100 on each surface.

The defendants counterclaimed for revocation (UPC_CFI_1816/2025), conditional on a finding of infringement. The decision mentions parallel proceedings before the US District Court for the Eastern District of Texas. The oral hearing took place on 24 September 2026.

Question

How is the claimed Rpc value to be understood, and who bears the costs of a conditional counterclaim for revocation where infringement is rejected?

Decision

On construction, the Division holds that the claimed Rpc is the number of peaks counted over the measured length, without the normalisation to 1 cm that SK nexilis derived from the output of a measuring device. It refers to Court of Appeal case law on claim construction (Hefei v Grundfos, UPC_CoA_622/2025, para. 36; HUROM v Nuc, UPC_CoA_678/2025, para. 37). Infringement not being established, the action is dismissed, as is the request for production of evidence.

On costs, the Division holds that a conditional counterclaim for revocation is a direct consequence of the infringement action, since a defendant can only rely on invalidity by filing such a counterclaim. Its costs are not ‘unnecessary’ within Article 69(3) UPCA, contrary to the Munich Local Division on 13 January 2026. Where infringement is rejected, the claimant is the unsuccessful party in both proceedings, in line with the Paris Local Division (19 August 2026, UPC_CFI_301/2025, para. 99).

This applies at least where the condition is stated in the statement of defence or, at the latest, at the oral hearing before validity is argued on the merits. The Division leaves open the case of a condition introduced only after the Court’s preliminary opinion. SK nexilis is ordered to pay the costs agreed by the parties, EUR 1.1 million; the value in dispute is set at EUR 15 million for each action.

Key points for practice

• A claimed parameter is construed according to the method taught by the patent, not the default setting of a measuring device.
• A conditional counterclaim lets the defendant rank its defences without bearing the revocation costs if infringement is rejected.
• Mannheim departs from the Munich Local Division; Court of Appeal guidance is still awaited.
• The decision distinguishes the Court of Appeal’s ruling in Fujifilm v Kodak on a conditional counterclaim targeting the UK part of a patent.

Provisions applied

UPC Agreement

Articles 65, 69(1) and 69(3)

Rules of Procedure

Rules 25, 118.5 and 190

EPC

Article 69 and Protocol on its interpretation

Case law cited

Hefei v Grundfos (Court of Appeal, UPC_CoA_622/2025), HUROM v Nuc (Court of Appeal, UPC_CoA_678/2025), AorticLab v Emboline (Court of Appeal, UPC_CoA_40/2026, 17 August 2026), Fujifilm v Kodak (Court of Appeal, UPC_CoA_880/2025 and 882/2025, 2 June 2026), Munich Local Division (13 January 2026), Paris Local Division (UPC_CFI_301/2025, 19 August 2026).

Prepared by Dhenne Avocats from the official decision, consulted on 1 November 2026. The database is updated every week, on Friday. Only the official text is authoritative.