Yoon & Lee International Patent & Law Firm

IAM Research

The Patent 1000 focuses exclusively on patent practice and has firmly established itself as the definitive 'go-to' resource for those seeking world-class legal patent expertise.

Silver - Firms: prosecution

Major Korean and Japanese companies call on Yoon & Lee International Patent & Law Firm to prosecute some of their most important patent applications in the local market and to direct outbound filings. The side is part of the pool of patent attorney firms engaged by Samsung Electronics, and is active in filing overseas applications for the tech giant. The team warrants especial notice for its work on SEP briefs. In the chemicals space, Yoon & Lee counts top cosmetics brand AmorePacific as a patron. Byeong-Ok Song comes highly recommended for his long experience and international background – recent accounts he has landed include that of local drug maker Boryung Pharmaceutical.

Firm Profile

Yoon & Lee International Patent & Law Firm provides a comprehensive range of services for IP rights, including patents and trademarks, as well as consultation services for the management and enforcement of IP rights. The firm was founded in 1989 and became a limited liability company in 2017. Yoon & Lee offers optimised IP services for the benefit of its clients through close cooperation and teamwork that maximise the high levels of expertise and experience of its staff of 89, which includes more than 35 foreign and domestic patent attorneys and lawyers. The firm is particularly well known for its patent technical expertise and long-term relationships with its clients in that practice area.


The firm’s main specialisation is in patent prosecution, especially in the electronics and software, chemistry and biotech, and mechanical and mechatronics sectors. One of the firm’s major strengths in the patent sector is its technical knowledge and expertise; it employs a high percentage of patent attorneys and technical specialists in comparison with general law firms and other patent law firms in Korea (33 patent attorneys and 23 patent engineers). In particular, the firm offers an efficient and effective combination of patent attorneys (including a partner patent attorney with an LLM from the United States) with extensive experience, including substantial experience appearing before district courts and high courts, as well as the patent court. The firm also has technical advisers with advanced degrees (PhDs and other postgraduate qualifications) in their specialist subjects, including electrical engineering, electronics, communications, computer science, mechanical engineering, chemistry, biotechnology, pharmaceuticals, cosmetics and life sciences. Based on their strong technical knowledge, the firm’s specialists are often called to testify as expert witnesses in court cases.

Areas of expertise

Yoon & Lee has four patent teams, as follows:

  • electronics/telecommunications – including electric, electronics, image processing, software, the Internet of Things and artificial intelligence;
  • standard – communications standards (including 5G standard patents);
  • mechanics – including mechanical and mechatronics, optics, software-related inventions, semiconductors, 3D printing, electrical vehicles and vehicles; and
  • chemistry/biotech – including pharmaceuticals, cosmetics, biotechnology, chemical and biochemical.


Yoon & Lee provides the following services:

  • worldwide patent application and registration services (Patent Cooperation Treaty applications), worldwide utility model application and registration services, prior art searches, patentability searches and patent mapping;
  • watching services for foreign patents and publications, patent infringement analysis, patent invalidation analysis, patent invalidation trial and litigation, patent infringement trial and settlement negotiations;
  • licence agreements, assignments and other agreements involving all forms of IP rights, technology valuation, technology transfer and contract assistance; and
  • invention mining, providing diverse strategies for planning applications for patent and utility model rights, know-how management and translation services.

Trademarks and designs

Yoon & Lee has a tight-knit trademark and design group that is able to provide excellent and individualised services to all clients. The team is headed by a former trademark examiner at the Korea Intellectual Patent Office and also includes a US attorney who is able to provide an international perspective and meet the requirements and expectations of international clients. The team delivers a wide range of trademark and design services and acts for businesses, both Korean and from overseas, in all market sectors.


Yoon & Lee’s clients span the globe and most industry sectors; they range from major international companies with established global operations to small and medium-sized enterprises. Unlike in some larger practices, at Yoon & Lee the most experienced professionals, rather than junior staff, handle all cases – all the partner patent attorneys continue to be involved in case work. The firm is able to work in Korean, English and Japanese and provides translation services for these languages, as well as for all languages into/from Korean for both domestic and international clients. Yoon & Lee places great emphasis on client satisfaction by providing quick, accurate and specialised services to meet the individual requirements of clients and to build trust over the long term; this is reflected in the over 25-year long relationships the firm enjoys with major Korean and foreign companies.

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