Important update on intellectual property protection and back contact technology
Latest news on intellectual property, patent infringement and back contact technology are shaping the solar industry
Maxeon Solar Technologies— our former mother company and now continuing as our technology partner within the TCL Group—last week filed a new patent infringement lawsuit in Germany against Aiko Solar and several German distributors. This action underscores the importance of respecting IP rights and protecting innovation in high-efficiency solar solutions.
At TCL SunPower Global, we remain committed to advancing Back Contact technology, leveraging the intellectual property and decades of expertise originated at SunPower Corporation and further developed in the past years at Maxeon. This continuity ensures that you receive products based on legitimate, proven technology, combining innovation, reliability, and compliance with global IP standards.
We encourage all our partners and distributors to consult with their external counsel, review their portfolios and ensure they work with suppliers who provide strong IP protection—something we are fully committed to at TCL SunPower Global.
Maxeon Files Third Patent Infringement Lawsuit Against Aiko in Germany, with Four Aiko European Distributors Named as Co-defendants
Maxeon’s defense of its advanced Back Contact solar IP extends to infringement from Aiko 2nd and 3rdGeneration BC Products
According to IP ForeFront media sources, on December 10 local time, TCL Zhonghuan’s subsidiary Maxeon Solar Pte. Ltd. officially filed a new patent infringement lawsuit against Aiko Solar before the Munich Regional Court I in Germany. The lawsuit accuses Aiko and its European distribution network of infringing the German part of Maxeon’s core patent EP2297789B1 (referred to as "EP789"), covering particularly Aiko’s second-generation (Gen2) and third-generation (Gen 3) Back Contact (BC) solar module products currently sold in the European market.
This lawsuit follows Maxeon’s previous legal actions against Aiko, including a 2023 complaint filed before the Mannheim Regional Court concerning infringing EP2297788, and a 2024 complaint before the Unified Patent Court (UPC) Local Division in Düsseldorf regarding infringing EP3065184. All three patents belong to the same BC technology family.
This move marks the third litigation front that Maxeon has opened inGermany, following the Mannheim Court and the UPC. Amid industry-wide cyclicaladjustment and mounting pressure on PV companies, the outcome of this lawsuitcould reshape the competitive landscape of the European high-end solar module market.
Maxeon Seeks Comprehensive Relief, Adds Four Distributors as Defendants
The patent at the center of the case, EP789, relates to a “Trench process and structure for backside contact solar cells with polysilicon doped regions”, and is one of the foundational technologies underpinning high-efficiency BC solar cells. Maxeon is seeking a court order for Aiko and the other defendants to refrain from infringing activities (i.e., a permanent injunction), disclose sales data for the accused products, and compensate for damages. Maxeon also seeks the destruction of infringing inventory held in Germany.
Unlike previous lawsuits, Maxeon has not only targeted Aiko’s manufacturing and sales entities but has also named four major German PV distributors—Wattkraft GmbH & Co. KG, DWH Solutions GmbH, Memodo GmbH, and Tepto GmbH—as co-defendants. Notably, Wattkraft has long been a strategic partner for Aiko in Europe[1]. This move aims to exert compliance pressure across Aiko’s European distributor chain. Under German patent law, downstream distributors who sell infringing products can be liable for injunctions and damages, even if they are not manufacturers. By including distributors as defendants, this lawsuit serves as a wake-up call for all Chinese solar companies going global—future overseas competition must not only involve thorough Freedom-to-Operate (FTO) analysis of the products themselves but also include IP protection guarantees for downstream partners.
Why Munich?
The Munich Regional Court I is one of Europe’s most authoritative venues for complex technical patent disputes. Known for its efficiency, rigor, and proactive enforcement, the court typically holds its first hearing as early as 9 months after service of process. If the plaintiff prevails and posts a bond, the court may require the defendants to refrain from infringing while the case is under appeal. This could immediately halt the import, sale, or distribution of the infringing products, cutting off market access. For PV products with rapid iteration cycles and short market windows, this kind of “Munich speed” is a preferred route for swift judicial relief.
A Comprehensive Litigation Strategy Around the BC Patent Family
As n-type cell technologies become mainstream, IP disputes surrounding BC and TOPCon are increasingly prevalent. Back-contact (BC) design relocates all electrodes to the rear of the solar cell. Compared to conventional front-grid cells, BC technology eliminates front-side shading, enabling maximum light absorption, higher efficiency, and a cleaner aesthetic.
As early as 2004, SunPower Corporation (Maxeon’s predecessor) achieved the world's first commercial production of large-area IBC cells at its Philippines facility, reaching a peak efficiency of 21.5%, laying the foundation for modern BC structures and processes.
EP 2 297 789 B1 introduces an innovative trench‑based architecture for backside‑contact (BC) solar cells that dramatically improves performance under shading conditions. By etching wide trenches between polysilicon‑doped P‑and N‑regions, the design physically isolates high‑recombination junctions; strategically‑placed interruptions allow limited but controlled contact, reducing the reverse‑breakdown voltage while keeping forward efficiency high.
The new lawsuit in Munich represents the latest move in Maxeon’s systematic defense of its core BC patent family, following earlier actions in the UPC and Mannheim courts.
The three parallel lawsuits concerning BC technology are progressing across distinct jurisdictions:
- Mannheim Court is Germany’s traditional patent litigation hub, known for its technical rigor and authoritative rulings.
- UPC offers one-stop jurisdiction across 18 European countries.
- Munich Court, with its quick procedures, has recently gained global attention for issuing pan-European preliminary injunctions, such as in Regeneron v. Formycon, following EU guidance in the BSH v. Electrolux case. This landmark decision has greatly enhanced the court’s appeal to global rights holders.
Maxeon’s lawsuit delivers a direct blow to Aiko’s high-margin overseas business.
Respecting IP Rights: A Path Back to Healthy Industry Competition
Maxeon’s latest lawsuit in Munich underscores the deep-rooted challenges facing Chinese PV firms amid their transition pains.
The PV industry is mired in price wars and homogenized competition, largely due to insufficient R&D investment and weak IP protection. The essence of the "involution" lies in many players refusing to pay for innovation, instead opting for reckless expansion, cheaper materials, or compromised quality.
Although Chinese PV manufacturers dominate global capacity, real technological leadership requires adapting to international IP norms, shifting from scale-driven to technology-driven strategies. Without long-term R&D investment, the industry may fail to achieve profitability proportional to market share, surviving only through cost-cutting in a red ocean.
For any Chinese PV enterprise aiming for global impact, the only viable path is to respect IP, pursue positive innovation, and build a robust technology moat—the foundation for sustainable and healthy growth.
It is worth noting that commercial disputes often end in cooperation. In recent years, despite frequent patent disputes in the PV sector, we’ve seen a pattern emerge: a series of cases have ended in settlements and licensing agreements that enable shared value. Examples include the global settlement between Maxeon and Tongwei in late 2024, as well as recent reconciliations between Jinko and LONGi, and JASolar and Chint New Energy.
[1]AIKO and Wattkraft cooperate on the EU Market for Distributed PV, https://aikosolar.com/en/news-aiko-and-wattkraft-cooperate/