OCI Wins Patent Battle Against Wacker Chemie

South Korean Supreme Court upholds invalidation of polysilicon patent

(Source: https://www.oci.co.kr/en/products/semiconductor/polysilicon)

South Korea's Supreme Court has dismissed the appeal by Germany's Wacker Chemie AG, effectively ending a long-standing patent dispute with South Korea's OCI. The case centered around Wacker's patent for the "Process for Production of Polycrystalline Silicon" (KR1356678), which OCI successfully invalidated.

The final ruling in January 2024 followed Wacker Chemie's unsuccessful attempt to overturn a 2020 Patent Court decision that had declared the patent invalid. Wacker had challenged the ruling in the Supreme Court, but their appeal was rejected, confirming the lower court's decision.

The legal battle began in 2017 when Wacker Chemie sued OCI for patent infringement at the Seoul Central District Court. After losing the case in November 2019, Wacker appealed to the Patent Court but faced another setback when the court ruled the patent invalid later that year. 

OCI had initiated the invalidation process by filing a request for patent nullification with the Korean Intellectual Property Trial and Appeal Board (KIPTAB) in 2017, targeting claims 1–8 of the patent. KIPTAB sided with OCI in October 2018, rendering the patent invalid.

Wacker Chemie continued to fight the decision through the South Korean legal system, filing appeals with the Patent Court in 2018 and subsequently with the Supreme Court in 2020. However, with the Supreme Court's final dismissal of the appeal, Wacker Chemie withdrew its remaining legal challenges in February 2024, marking the conclusion of the dispute and the expiration of the patent.