Heraeus Electronics v Vibrantz (CoA, 16 September 2026)

Dhenne Avocats · 10 October 2026

Our analysis

Summary

By decision of 16 September 2026, given in the joined appeals UPC_CoA_919/2025 (infringement action) and UPC_CoA_920/2025 (counterclaim for revocation), the Court of Appeal held the cross-appeals of Heraeus Electronics and Vibrantz against the Munich Local Division’s decision of 10 October 2025 on EP 3 215 288 (metal sintering preparation) admissible but unfounded (paragraph 22). It laid down four principles: res judicata of a national decision is an absolute bar to the continuation of proceedings which the parties cannot waive, its scope is governed by national law, a substantiated denial under Rule 171.2 RoP cannot be required for facts outside a party’s sphere of knowledge, and use that is lawful in one Member State under a prior-use right cannot establish a threat of infringement in another. The decision settles how the UPC deals with a patent already partly revoked by a national court. On the merits, the Court upheld the validity of claim 1 in the maintained version, Vibrantz’s prior-use right in Germany and the absence of any threat of infringement in France, Italy and Romania. Each appellant bears the costs of its own appeal, and the value of each appeal is set at EUR 1,000,000.

Facts and procedure

Heraeus sued Vibrantz for direct and indirect infringement in Germany, France, Italy and Romania. By judgment of 7 November 2023 the German Federal Patent Court had partly revoked the German part of the patent. The appeal against that judgment was withdrawn. The Munich Local Division dismissed the infringement action because of a prior-use right in Germany and the absence of pleaded acts in the other three countries. It held the counterclaim inadmissible for the German part insofar as it relied on lack of novelty and inventive step, and revoked the patent for France, Italy and Romania beyond the version maintained by the Federal Patent Court (paragraph 14). On appeal Heraeus sought a finding of infringement, an injunction and provisional damages of EUR 250,000, Vibrantz sought full revocation for all four countries (paragraphs 15 to 17).

The applicable law

The Court relied on Rule 362 RoP (absolute bar), Art. 36(1) of Regulation 1215/2012 and Arts 24 and 83 UPCA to identify the law governing the effect of a national decision (paragraphs 84 to 101). It applied sections 322 and 325 of the German Code of Civil Procedure and section 22 of the German Patent Act to the scope of the Federal Patent Court’s judgment, and Art. 138(1) EPC to the grounds for revocation (paragraphs 102 to 106).

Question

Does the national judgment of partial revocation bar the counterclaim for revocation of the German part, and to what extent? How is the feature « zum festen Verbinden » in claim 1 to be construed?

Decision

Res judicata is an absolute bar which the Court raises of its own motion (paragraphs 84 to 87). Its scope is governed by German law, which infringes neither the right to be heard nor Art. 47 of the Charter, the request for a preliminary reference to the CJEU was refused (paragraphs 88 to 101). The judgment binds Vibrantz as successor in title. Under German law it covers only the grounds raised, the grounds under Art. 138(1)(a) EPC forming a single subject matter: the counterclaim is inadmissible for the German part as regards patentability but admissible as regards insufficiency and lack of clarity (paragraphs 102 to 107). As Heraeus defended only the version maintained by the Federal Patent Court, claim 1 as granted was revoked without examination on the merits (paragraph 108). « Zum festen Verbinden » means a stable connection, without any numerical strength threshold, the mathematical product in claim 1 being the functional parameter (paragraphs 39 to 66).

Claim 1 is sufficiently disclosed: using a preparation with the claimed mathematical product is enough to achieve the stable connection, without trial and error or any numerical threshold (paragraphs 116 to 128). Lack of clarity is not a ground for revocation, but it is examined for a feature added after grant. « Zum festen Verbinden » introduces no lack of clarity (paragraphs 132 to 136). The JD 15 sales presentation discloses neither the claimed proportions, nor the coating, nor the methods for measuring tap density and specific surface area (paragraphs 149 to 161). The objective problem is to provide an alternative, which does not rule out inventive step. Starting from JD 24, which attributes the stability of the bond to a sintering aid, the skilled person had no reason to look at tap density and specific surface area, whether alone or with JD 15 or JD 17, and it is for the counterclaimant to prove the absence of a technical effect or that the range was arbitrary (paragraphs 203 to 269). Claims 2 to 8, not argued on appeal, are not at issue (paragraphs 270 and 271). Art. 28 UPCA refers to national law, so prior use in Germany is governed by section 12 of the German Patent Act (paragraphs 289 to 292). Before the priority date Vibrantz had made 45 sintering pastes under two base recipes using SF30 and SF70A flakes, retained samples of which, measured by the claimed methods, show a product within the range: objective and subjective possession of the invention is established, without any need to have understood its effect, and the right covers the attacked product, other batches and method claim 5 (paragraphs 302 to 338). A party may plead lack of knowledge of a fact outside its sphere, such as the origin of the samples, but must specifically contest what it is able to assess (paragraphs 315 to 322). The Rule 36 RoP request to file new material was refused as irrelevant (paragraph 339). With no pleaded acts in France, Italy and Romania, lawful use in Germany creates no risk of infringement and no imminent infringement was shown (paragraphs 347 to 353). The first-instance cost split (60:40) was upheld (paragraph 354).

Key points for practice

• A final national revocation decision binds the UPC according to the law of the State in which it was given. Grounds not raised before the national court remain available.
• A party may plead lack of knowledge of facts outside its sphere without those facts being deemed uncontested under Rule 171.2 RoP.
• A national prior-use right, assessed under the law of the State concerned (Art. 28 UPCA), rules out a threat of infringement in other Member States, since there is no unlawful use (paragraphs 289 to 292 and 351).
• Practical point: before filing a counterclaim, check which grounds a national court has already decided on the same patent and whether the counterclaimant is a successor in title of the party that brought those proceedings.

Provisions applied

Agreement on a Unified Patent Court

Arts 24(1)(a) and (e), 28, 65(2), 69(1) and 83

Rules of Procedure

Rules 30.1(b), 36, 171.2, 222.1, 222.2 and 362

European Patent Convention

Arts 54, 56, 84 and 138(1)

Other provisions

German Patent Act (PatG), sections 12 and 22, German Code of Civil Procedure (ZPO), sections 322 and 325

Regulation (EU) No 1215/2012

Arts 36(1) and 71a

Case law cited

Court of Appeal: Nanostring v 10x Genomics, 26 February 2024, Insulet v EOFlow, 30 April 2025, Mammut v Ortovox, 25 September 2024, SharkNinja v Dyson, 3 December 2024, Fives v REEL, 16 January 2025, Belkin v Philips, 3 October 2025, ONWARD v Niche, 27 March 2026, Abbott v Sinocare, 17 April 2026, Angelalign v Align, 8 July 2026, Fujifilm v Kodak, 13 July 2026, Kodak v Fujifilm, 2 June 2026, Knaus Tabbert v Yellow Sphere, 17 August 2026, Meril v Edwards, 25 November 2025, Amgen v Sanofi, 25 November 2025, Sinocare v Abbott, 30 March 2026, Abbott v Sibio, 14 February 2025, Boehringer Ingelheim v Zentiva, 13 August 2025, Dyson v Dreame, 6 March 2026, Sumi v Syngenta, 3 March 2025.

Related decisions

• Heraeus Electronics v Vibrantz, 10 October 2025, Munich Local Division decision under appeal.

Prepared by Dhenne Avocats from the official decision, consulted on 10 October 2026. The database is updated every week, on Friday. Only the official text is authoritative.