On 2 June 2026, the Patent Reexamination and Invalidation Department of the China National Intellectual Property Administration (CNIPA) rendered decisions declaring two patents in the photovoltaic (PV) silver paste sector entirely invalid. Over the past several years, cumulative claims arising out of litigation involving these two patents have reached RMB 1 billion, implicating multiple leading industry players and imposing substantial litigation pressure on China’s domestic PV silver paste industrial chain. These two invalidation decisions are set to exert a material impact on the development of the industry.
Case Background
When Liu Shen was retained, the client was at a critical juncture of major asset restructuring. Taking advantage of this window, a competitor-initiated patent infringement proceedings seeking damages of up to RMB 200 million. Faced with this high value litigation at such a sensitive moment, the client was exposed to heightened legal risks and commercial pressures.
Breaking the Deadlock to Achieve a Favorable Outcome
Upon receiving the mandate, Liu Shen Shenzhen Office immediately formed a dedicated task force in close coordination with the firm's Chemistry & Materials Practice Group. The subject patents were owned by a long established foreign industry player with counterpart patents granted across multiple jurisdictions worldwide. Notably, one of the two patents had survived a prior invalidation proceeding and been maintained. The patentee also asserted that its related products had received prestigious industry awards, which had led to a general perception that the patents possessed robust stability. Refusing to take such prior credentials at face value, while concurrently defending the infringement suit, the Liu Shen team leveraged its deep rooted materials expertise and extensive track record in patent invalidation work. The team conducted in depth analysis of the technical history disclosed in the patent documents, comprehensive research into prosecution histories of related and family patents, and exhaustive searching and review of technical literature across the relevant field. Internal flaws in both patents were identified in multiple dimensions, including insufficient technical ingenuity and deficiencies in patent drafting.
To fully demonstrate these defects before CNIPA, the team assembled more than 20 pieces of evidence and developed a well rounded set of invalidation grounds and strategies. From multi faceted perspectives, the team analyzed the misalignment between patent claims and the technical contributions alleged by the patentee, and unpacked inherent technical contradictions among data from dozens of working examples set forth in the specification. Supplementary experimental data was introduced to reinforce persuasiveness. Through analysis of related patent applications and extensive prior art references, the team further established issues with novelty and inventive step of the subject patents. The sophisticated interplay among different invalidation grounds left the patentee unable to present a consistent and coherent line of argument during the oral hearing.
Furthermore, the team performed granular review of 30 counter evidence submissions furnished by the patentee. By dissecting flaws in each piece of counter evidence one by one, the firm effectively defeated the patentee’s tactic of obfuscating technical details. Facts and arguments advanced by our side were further corroborated using content extracted from the patentee’s own counter evidence. Ultimately, both patents were fully invalidated on the ground that the claims were not supported by the specification.
Case Significance
This victory in the patent invalidation proceedings has lifted the threat of massive litigation against the client and will exert far reaching influences on the competitive landscape of the industry. The case demonstrates Liu Shen’s formidable capabilities in handling complex technology intensive IP disputes. The firm’s corporate style management model enables efficient cross team collaboration and multi dimensional deployment of resources. Its deep talent pool supports precise evaluation of technical boundaries and legal hurdles, enabling delivery of integrated solutions covering patent invalidation, counter litigation and compliance system development. This matter serves as a strong practical precedent for enterprises confronted with patent sniper litigation featuring exorbitant damage claims.
Project Team
Shenzhen Office: AN Zhifei, LIU Zhijie, ZENG Yunpeng, YAN Jiajia
Chemistry & Materials Practice Group: SONG Li, ZHAN Chengbin, YANG Qian, JIN Nican, YANG Yan, LI Zhen
