January 13, 2026
I. Overview
Two related proceedings between the same parties—an infringement action and the corresponding counterclaim—arise from a single patent dispute concerning European Patent EP 2 787 541, which relates to TOPCon-based solar cell technology. The dispute is between the Chinese solar panel manufacturers JingAo Solar Co., Ltd. (Claimant) and Chint New Energy Technology Co., Ltd. / Astronergy, together with its German and Dutch subsidiaries (Defendants). Both cases were heard by the Munich Local Division of the Unified Patent Court (UPC).
Procedural Order – UPCCFI425/2024
Key Decision Date: March 31, 2025
Key Takeaways:
- Patent amendments not restricted to counterclaim grounds: The patentee may request amendments that are not directly related to the grounds for invalidity asserted in the counterclaim for revocation. Rule 30 RoP aims to give patentees the opportunity to “save” their patent in amended form.
- Synchronization with EPO proceedings: UPC proceedings should be harmonized with EPO proceedings, especially regarding claim amendments (Rule 295(a) RoP). Claim versions amended by the EPO can be introduced into UPC infringement proceedings.
- Auxiliary requests from EPO can be introduced: The Munich Local Division allowed the patentee to introduce auxiliary requests that had been upheld by the EPO Opposition Division into UPC infringement proceedings.
- New infringing embodiments: The Court allows flexibility for patentees to address newly discovered infringing activities during proceedings.
Final Decision – UPCCFI425/2024 (Infringement) and UPCCFI751/2024 (Counterclaim for Infringement)
Decision Date: November 28, 2025
Outcome: The Munich Local Division, presided by Dr. Matthias Zigann, found that Chint/Astronergy had infringed EP 2 787 541 with their ASTRO N series solar modules.
Key Context:
- The patent relates to TOPCon (Tunnel Oxide Passivated Contact) technology, which defendants argued constitutes the standard for the solar panel market, capturing 70-80% of the PV market
- The EPO had upheld the patent (EP 541) at first instance in October 2024, with appeal proceedings ongoing
- There were parallel proceedings at the Hamburg Local Division regarding a related patent EP 759, which was later revoked by the EPO
II. Detailed Information on Some Important Aspects
II-1. Claim Construction
a. Basic Rule
In UPCCFI425/2024 and UPCCFI751/2024, the Munich Local Division applied the established UPC approach to claim construction in accordance with Article 69 EPC and its Protocol on Interpretation, which treats the patent claim as not only the starting point but the decisive basis for determining the scope of protection. The Court confirmed that the interpretation of a patent claim does not depend solely on the strict, literal meaning of the wording used, but must take into account the description and drawings.
b. Claim Construction is not Strictly Bound by Party Submissions.
The Munich Local Division held that reference to dependent claims by the parties for the first time during oral proceedings for the interpretation of independent claims may not be considered late, because the interpretation of a patent claim is a matter of law and the Court must independently construe the claims. This principle allows parties to rely on dependent claims as interpretive aids even at the oral hearing stage, provided they support arguments already in dispute, which reflects the UPC’s recognition that claim construction is ultimately a judicial function rather than being strictly bound by party submissions.
II-2. Extended Subject Matter in the Counterclaim for Revocation
a. Basic Rule
The UPC has clarified its approach to the substantive assessment of added matter in line with EPO practice under Article 123(2) EPC: as confirmed by the Court of Appeal in UPCCoA382/2024 (Abbott/Sibio), the content of an application must not be treated as a reservoir from which features pertaining to separate embodiments could be combined to artificially create a particular embodiment not disclosed in the application as filed – the so-called prohibition on inadmissible intermediate generalisation. In the parallel EPO proceedings concerning EP 4 092 759 (a related JingAo patent in the same technical field), the Opposition Division revoked the patent entirely due to added matter, demonstrating the strict application of these principles.
b. Timing for Filing Revocation Objections (Extended Subject Matter)
Regarding the handling of extended subject matter (added matter) objections in the counterclaim for revocation, the UPC’s front-loaded procedural system imposes strict requirements on when such objections can be raised. The Rules of Procedure on amendments apply equally to counterclaims for revocation as to infringement actions, with no leniency afforded to counterclaimants – all grounds for revocation and supporting documents must be included with the initial counterclaim. In related UPC jurisprudence, such as the DexCom v. Abbott case (UPCCFI395/2023), the Paris Local Division refused to admit an added matter objection raised for the first time in the rejoinder, finding no legitimate reason to raise a new ground for revocation at such a late stage of proceedings.
II-3. Infringement Argumentation
a. “De Facto Standard” Argument”
On the infringement analysis, the Munich Local Division in its November 28, 2025 decision found that Chint/Astronergy had infringed EP 2 787 541 with their ASTRO N series solar modules, which employ TOPCon (Tunnel Oxide Passivated Contact) technology for enhanced solar cell efficiency. The defendants’ primary argument centred on the contention that TOPCon technology had become the de facto industry standard, claiming it would capture 70-80% of the photovoltaic market in coming years, which appeared to be a precursor to potential FRAND-style arguments or an attempt to characterize the patent as covering essential technology that should be licensed broadly. However, the Court noted that this market forecast was merely speculative and not supported by valid figures, effectively rejecting the argument’s factual premise.
b. Interplay Between UPC Infringement Proceedings and Parallel EPO Opposition
The case also illustrates the importance of parallel EPO proceedings: while the EPO Opposition Division upheld EP 541 at first instance in October 2024 (with appeal proceedings ongoing and a Board of Appeal provisional opinion issued on October 23, 2025), the UPC was able to proceed to an infringement finding based on the patent as maintained, with the patentee having been permitted to introduce auxiliary requests upheld by the EPO into the UPC proceedings under Rule 30 RoP.
II-4. Security for Costs Involving Non-EU Parties
a. Security for Costs before the Local Divisions: Munich vs. Hamburg
The security for costs dispute in UPCCFI425/2024 arose when the defendants Chint New Energy Technology Co., Ltd. and its Astronergy subsidiaries filed an application under Rule 158 RoP requesting that JingAo Solar, as a Chinese-domiciled claimant, provide security for the defendants’ potential legal costs, arguing that enforcement of any UPC costs decision in the People’s Republic of China would be impossible or unduly burdensome. JingAo Solar countered that the applicants had not provided any substantive arguments for their “speculative allegation” and that requiring security based solely on the claimant’s registered office in a non-EU/non-EEA country would constitute a form of a priori discrimination based on nationality, which is not provided for in any source of law. The Munich Local Division, in its order of March 19, 2025, acknowledged that the mere fact of residence in China could appear discriminatory, but held that the decisive factors under Article 69(4) UPCA and Rule 158.1 RoP are whether the claimant’s financial position raises legitimate concern about recoverability of costs, and/or whether a costs order would likely be unenforceable or enforceable only in an unduly burdensome way. The Court then examined concrete evidence of enforcement difficulties, noting that European courts have faced significant problems serving documents in China despite China’s ratification of the Hague Service Convention: the Higher Regional Court Munich (GRUR-RR 2020, 511), the Mannheim Local Division (UPCCFI332/2024), and UPC provisional measures cases (UPCCFI508/2023 and UPCCFI509/2023) all experienced requests for service being either not forwarded, objected to and returned, or remaining unanswered for more than six months without apparent reason. On this basis, Munich ordered JingAo to provide security of €200,000, calculated according to costs reimbursable for a value in dispute up to €2 million.
Notably, the Hamburg Local Division reached the opposite conclusion just two weeks later in a related case between the same parties (UPCCFI429/2024), holding on April 2, 2025 that security for costs cannot be ordered simply because the claimant is domiciled in China, and that the “sole reference to the past difficulties of service under the Hague Service Convention in Germany as a member state does not provide sufficient reasons” for such an order. Hamburg’s panel emphasised that defendants must demonstrate more than general allegations about enforcement difficulties, explicitly distancing itself from Munich’s approach. When Chint sought panel review of Hamburg’s dismissal on May 9, 2025, the Hamburg panel rejected the application, stating that the defendants had not put forward any new convincing arguments.
b. Court of Appeal Resolution and Implications for Non-EU Claimants
The Court of Appeal resolved this divergence in a precedential decision on July 9, 2025 (UPCCoA431/2025), reversing the Hamburg Local Division and siding with Munich’s approach. The Court of Appeal held that “the finding that due to the recent establishment of this Court there is currently no experience with enforcing costs decisions of this Court in a particular country, does not rule out the possibility that enforcing a cost decision in that country may prove to be impossible or unduly burdensome”. The Court emphasised that in the absence of enforcement experience, the court must examine the likelihood of successful enforcement based on other facts and circumstances, and that a party’s registered office in a non-EU/non-EEA country is a relevant factor since EU law guarantees recognition and enforcement of judgments among Member States, but similar guarantees may not exist for non-EU states. The Court of Appeal noted that JingAo had failed to state and demonstrate that its financial resources were such that the difficulties in providing security should outweigh Chint’s legitimate interest in obtaining security for costs, and ordered security of €200,000. This decision has broader implications for UPC litigation involving non-EU parties, particularly Chinese companies, as it establishes that documented difficulties with service of process under the Hague Convention and lack of precedent for UPC costs enforcement can justify security orders even without proof of the claimant’s financial inability to pay.
Authors
Dr. Mirko Schacht
Mingyan Xi