Yon-Sun W. Sohn focuses her practice on complex commercial disputes, with an emphasis on intellectual property litigation. She previously served as a law clerk to Judge Michael H. Schneider of the US District Court for the Eastern District of Texas for two years. Yon represents clients in a wide range of technical fields, from oil and gas to automotive industries.
Yon serves clients throughout the entire litigation process. She has experience in every phase of litigation, including pre-litigation counseling and due diligence, pleadings and venue or jurisdictional motions, managing written, oral, and expert discovery, claim construction briefs and dispositive motions, trial, and post-trial briefing.
Yon has experience representing clients in trade secrets disputes, under both state statutory and common law as well as Federal Defend Trade Secrets Act. She understands the unique challenges of litigating trade secrets disputes from both the plaintiff's and the defendant’s side, and has a keen understanding of licensing, noncompete agreements, nondisclosure and confidentiality agreements, employee defections, and industrial espionage issues that often arise in trade secrets litigation.
In addition to her litigation practice, Yon engages in full-service IP counseling for her clients. As a Registered Patent Attorney, Yon has experience prosecuting patents for a wide spectrum of clients—from Fortune 500 companies to individual inventors. She also regularly counsels clients regarding trademark issues.
Prior to joining Morgan Lewis, Yon was an IP litigator at another large international firm, where she represented clients in numerous patent, trademark, trade secrets, copyright, unfair competition, and breach of contract disputes. During her clerkship in the Eastern District of Texas—one of the busiest patent litigation dockets in the US—Yon oversaw and managed hundreds of patent cases and other complex civil and criminal cases. Prior to her clerkship, Yon represented clients in patent prosecution, IP portfolio management, trademark and domain name disputes, and pre-litigation counseling.
While Yon has technical degrees in materials engineering and chemistry, she represents clients in numerous sectors including the oil and gas, software, electronic devices, medical devices, food processing, biotechnology, and automotive.
Represent a major agrochemical company in a dispute against a licensee that breached a patent license agreement.
Represented an oilfield engineered solutions company in a patent infringement case against a competitor in the Eastern District of Texas.
Represented an electronics company in a patent infringement case against a competitor in the Central District of California. The client settled the case favorably after serving the infringement contentions.
Represented a media streaming company as a third-party in a patent infringement case asserted by a non-practicing entity (NPE) in the Eastern District of Texas. The client avoided having to comply with the discovery request a, with a potential exposure of being targeted by the NPE.
Represented an oilfield tubular solutions company in a bet-the-company patent infringement case against a competitor, in which the defendant asserted an antitrust counterclaim. The client prevailed on all claims that went to trial in the Southern District of Texas.
Represented a major international automotive company in inter partes review (IPR) proceedings in response to a patent infringement allegation by an NPE in the Eastern District of Michigan. The client settled the both the district court case and the IPR proceedings favorably after filing several IPR petitions.
Defended a major social media company in a patent infringement case by an NPE in the Eastern District of Texas. The client settled the case favorably.
Defended a social media company in a patent infringement case by an NPE in the Eastern District of Texas. The client settled the case favorably after serving the invalidity contentions.
Represented a dental appliance company in a potential patent infringement dispute against a former employee who created a competing company.
Represented a major interior fixtures company in design patent infringement disputes against several competitors.
Represented an oilfield services company in prosecution of a utility patent for high-efficiency flare system.
Represented a major international food processing company in prosecution of worldwide portfolio of utility and design patents in food chemistry, manufacturing processes and systems, imaging and quality-control system, and product design.
Represented a medical device company in prosecution of several utility patents on nebulizer technology.
Represented a major mobile phone company in prosecution of utility patent on antenna technology on cellular devices.
Represented a medical device company in prosecution of utility patent on implantable transponder device.
Represented a major climate-control equipment manufacturer in prosecution of control systems.
Defended an immersive video equipment company in patent infringement allegation involving 360-degree video technology.
Defended a direct-selling company in against allegations of misappropriation of trade secrets, false advertisement, breach of contract, and tortious interference claims.
Counseled an oil country tubular goods company regarding trade secret protection in the steelmaking industry.
Represented a multi-state board that administers standardized licensing exams in trade secret misappropriation case against test prep companies.
Represented a software developer in a trade secret misappropriation case against a competitor.
Represented an oilfield tubular solutions company in a trade secret misappropriation case against a competitor.
Represented an oilfield software company in a trade secret misappropriation case against a competitor.
Represented a major toy company in several investigations of pre-release leaks of highly anticipated toys and related marketing materials.
Complex Commercial Litigation
Represent an oilfield services company asserting a breach of license agreement and tortious interference claims against the licensee company and a competitor that acquired the licensee company.
Defended a life insurance company against policy holders asserting claims of breach of contract, fraudulent inducement, violation of Insurance Code, and Deceptive Trade Practices Act.
Represented an oil-and-gas exploration and production company in the Northern District of Texas in a case against a former partnering company for breach of a gas gathering agreement.
Represented an oil-and-gas exploration and production company before the Texas Railroad Commission in flaring permit proceeding contested by an energy infrastructure company that claimed rights in the gas to be flared.
Defended a solar energy company in two related cases in the Western District of Texas and Texas state court in a rural county involving a breach of contract claim.
Represented an oilfield tubular solutions company asserting breach of contract, breach of fiduciary duty, and unfair competition claims against former employees who started a competitor company.
Trademark & Trade Dress
Counseled a major international oil-and-gas company regarding trademark enforcement.
Represented an oil country tubular goods company in trademark infringement case against a competitor palming off inferior goods and falsely advertising as being associated with the client company. The defendant company agreed to a consent decree shortly after the lawsuit was filed.
Represented a leading manufacturer of cigarette papers in counterfeiting case against wholesalers. The court granted ex parte seizure order for the counterfeit goods, and the client secured a default judgment as a sanction against the defendants for their litigation conduct.
Represented a major interior fixtures company in various trademark and trade dress disputes against counterfeiting, gray-market goods, and unauthorized distribution outside the licensed channels.
Represented an auto body shop seeking to adopt a franchise model, and drafted a new set of franchise agreement and associated trademark license agreements and monitoring protocols.
Represented domain name owners whose domain names were hijacked, and filed Uniform Domain Name Dispute Resolution Policy (UDRP) petitions.
Represented an interactive media equipment company in trademark infringement dispute against a user of the same mark in a related industry.
Represented a multi-state board that administers standardized licensing exams in copyright infringement case against test prep companies in the Southern District of Texas.
Counsel a dental appliance company in a potential copyright infringement dispute against a former employee who started a new competing company and used marketing presentations copied from that of the client.
Represented a major toy company against unlicensed users of copyright-protected marketing materials.
Counsel an oilfield services company regarding copyrighting documents related to a proprietary software.
Southern Methodist University Dedman School of Law, 2012, J.D., cum laude
University of Nevada, Reno, 2008, M.S., Metallurgical Engineering
University of Nevada, Reno, 2006, B.S., Professional Chemistry, magna cum laude
University of Nevada, Reno, 2006, B.S., Materials Science & Engineering, magna cum laude
US Court of Appeals for the Fifth Circuit
US District Court for the Northern District of Texas
US District Court for the Eastern District of Texas
US District Court for the Southern District of Texas
US District Court for the Western District of Texas
US Patent and Trademark Office
Clerkship to Judge Michael H. Schneider of the US District Court for the Eastern District of Texas (2013 - 2015)
Judicial Extern to Judge Terry R. Means of the US District Court for the Northern District of Texas (2012)
Awards and Affiliations
Member, Litigation Department of the Year–Intellectual Property, The American Lawyer (2019)
Member, Association of Former Law Clerks of the Eastern District of Texas
Member, State Bar of Texas, Intellectual Property Section, Trademark Committee (Co-Chair, Houston Roundtables)
Member, American Intellectual Property Law Association