[News] Maxeon Sues Aiko in Third German BC Patent Case: Targets Distributors and BC Products

Munich, Germany – December 10, 2025 – Maxeon Solar Pte. Ltd., a subsidiary of TCL Zhonghuan Renewable Energy Technology Co., Ltd., has initiated a new BC patent infringement lawsuit against Aiko Solar in the Munich Regional Court I, alleging violations of the German portion of its core patent EP2297789B1 ("EP789"). The suit targets Aiko's second-generation (Gen 2) and third-generation (Gen 3) back-contact (BC) solar module products currently sold in the European market.

This action builds on Maxeon's prior legal efforts against Aiko, including a 2023 lawsuit in the Mannheim Regional Court involving patent EP2297788 and a 2024 case in the Unified Patent Court's (UPC) Düsseldorf Local Division concerning patent EP3065184. All three patents belong to the same BC technology family, marking Maxeon's third litigation front in Germany amid the photovoltaic (PV) industry's cyclical downturn and mounting pressures on companies.

The outcome of this lawsuit could reshape the competitive landscape in Europe's high-end solar module market.

Four Distributors Added as Defendants, Maxeon Seeks Comprehensive Relief

The disputed patent, EP789, describes a "trench process and structure for backside contact solar cells with polysilicon doped regions," a foundational technology for high-efficiency BC batteries. Maxeon is seeking a court order for Aiko and the other defendants to cease infringing activities (equivalent to a permanent injunction), disclose sales data for the implicated products, and provide compensation for the infringement. Additionally, Maxeon requests the destruction of infringing inventory held by the defendants' distributors in Germany.

In a strategic move, Maxeon has not only targeted Aiko's manufacturing and sales entities but also named four prominent German PV distributors as co-defendants: Wattkraft GmbH & Co. KG, DWH Solutions GmbH, Memodo GmbH, and Tepto GmbH. Wattkraft, in particular, has been a long-term strategic partner of Aiko in Europe. This approach aims to impose compliance pressures on Aiko's European supply chain.

Under German patent law, downstream distributors can be held liable for halting infringement and paying damages if they sell infringing products, even if they are not the manufacturers. By including Aiko's distributors, Maxeon sends a clear message to all Chinese PV companies entering overseas markets: Beyond conducting Freedom-to-Operate (FTO) analyses for products, firms must also provide robust intellectual property assurances to their downstream partners.

Why Munich?

The Munich Regional Court I is renowned in Europe for handling complex technical patent disputes with efficiency, rigor, and proactive enforcement. From the date of service, the first hearing is typically scheduled within about nine months, featuring a streamlined and expedited process.

If the plaintiff prevails and posts a bond, the court can mandate that the defendant cease infringing activities during an appeal, effectively halting sales and imports. For fast-evolving PV products with short market windows, this "Munich speed" makes it a preferred venue for rights holders seeking swift judicial remedies.

Strategic Litigation Layout Around Core BC Patent Family

As N-type battery technologies dominate the market, intellectual property disputes over BC and TOPCon innovations are surging. Back-contact technology places all electrodes on the solar cell's rear side, eliminating front-side shading losses to maximize sunlight utilization, achieve higher conversion efficiencies, and offer a more aesthetic appearance compared to traditional front-grid designs.

As early as 2004, SunPower Corporation (Maxeon's predecessor) achieved the world's first commercial mass production of large-area IBC batteries at its Philippine facility, reaching a peak efficiency of 21.5% and establishing the foundational structure and processes for subsequent BC technology routes.

Patent EP2297789B1 introduces an innovative trench-based BC solar cell architecture that significantly enhances performance under shading conditions. By etching wide trenches between polysilicon-doped P and N regions, it physically isolates high-recombination junctions; strategically placed interruptions allow controlled contact, maintaining forward efficiency while reducing reverse breakdown voltage.

This Munich lawsuit is the latest in Maxeon's systematic and strategic defense of its core BC patent family. Previous actions in the UPC and Mannheim courts have run parallel, leveraging distinct jurisdictional strengths: Mannheim's expertise in detailed technical reviews and infringement determinations; the UPC's "one-stop" model for enforcing across 18 countries; and Munich's "rocket docket" style, recently bolstered by a landmark EU Court of Justice ruling in BSH v. Electrolux, enabling Munich's issuance of Germany's first pan-European cross-border preliminary injunction (as in Regeneron v. Formycon). This development has heightened Munich's appeal to global rights holders.

Aiko Solar, a rising Chinese PV player, has rapidly advanced in BC technology with its All-Back-Contact (ABC) approach, touted for efficiency and aesthetic benefits. Its Gen 2 series, launched in 2023-2024, incorporated "full-screen" upgrades to boost output to 680W-700W. The Gen 3 "Infinite" series, released in 2025, achieves mass-production efficiencies of 25%, with some 78-cell modules exceeding 800W. These high-performance products have gained traction in overseas markets like Europe, where Aiko's module sales abroad reached 55% by Q3 2025. Maxeon's lawsuit strikes at Aiko's lucrative premium overseas segments.

Respecting IP to Foster Healthy Competition in PV Industry

Maxeon's latest enforcement push in Munich highlights deeper challenges facing Chinese PV firms during a transitional pain period.

The industry is mired in price wars and homogenization, rooted in insufficient emphasis on innovation and IP protection. "Involution" stems from participants' reluctance to invest in R&D, opting instead for unchecked expansion, cost-cutting, or quality compromises in low-level competition.

While Chinese PV companies dominate global capacity, securing core industry influence requires adapting to international IP norms and shifting from scale-driven to technology-driven strategies. Without overcoming short-sighted R&D attitudes and embracing cost-based rivalry, the sector risks slim profits mismatched to its market share, surviving only by squeezing margins in a "red ocean."

For all PV enterprises eyeing global competition, respecting IP, committing to original R&D, and building genuine technological moats are essential for sustainable, healthy growth.

Notably, commercial rivalries often culminate in collaboration. Recent PV BC patent disputes—from Maxeon's global settlement with Tongwei Co., Ltd. in late 2024 to JinkoSolar's reconciliations with LONGi Green Energy and JA Solar, and Chint New Energy's with Astronergy—demonstrate that litigation frequently evolves into licensing agreements, fostering shared benefits and reordering the industry.

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