First success for Chint in solar tech case as EPO revokes JingAo Solar patent

The Opposition Division at the European Patent Office has revoked a patent at the centre of a dispute between Chinese solar panel manufacturers Chint and JingAo Solar. The decision could impact an upcoming hearing at the Unified Patent Court.

The dispute between Chint and JingAo Solar concerns the latter’s EP 2 787 541 and EP 4 092 759. The patents relate to TOPCon technology, a new generation of solar cell innovation.

TOPCon (Tunnel Oxide Passivated Contact) describes a specific solar cell structure. The technology, developed at Fraunhofer ISE, uses an ultra-thin tunnel oxide combined with a thin silicon layer. According to the institute, this enables excellent charge carrier selectivity, increasing cell efficiency and performance even in poor lighting conditions.

The EPO’s Opposition Division has now declared EP 759 entirely invalid due to added matter. According to JUVE Patent sources, JingAo Solar plans to appeal the decision. The EPO upheld EP 541 at first instance in October 2024, though an appeal is pending.

UPC hearings

The parties are also fighting at the UPC, which has scheduled oral hearings for this autumn. JingAo filed an infringement action over EP 759 at the Hamburg local division in 2024 (case ID: UPC_CFI_429/2024). The court will hear this on 19 November.

The Chinese patent holder also filed a lawsuit over EP 541 at the Munich local division, which has scheduled a hearing for 28 October (case ID: UPC_CFI_425/2024).

In both cases, Chint and its subsidiary Astroenergy responded with a counterclaim for revocation and initiated parallel opposition proceedings at the EPO.