Strategies for Patent Invalidation Trials In Korea: A Guide for IP Managers

In today's rapidly changing technological landscape, the importance of patents as a core corporate asset is greater than ever. However, even a hard-won patent can be challenged on its validity at any time. Conversely, a competitor's patent can become a significant obstacle to your business activities. In these situations, the patent invalidation trial system serves as a crucial legal instrument for executing a company's IP strategy and gaining a competitive edge.

Today, Pine IP Firm will provide a detailed analysis of the Korean patent invalidation trial system, offering practical considerations for corporate IP managers. We hope this guide deepens your understanding and helps you leverage the system to enhance your company's intellectual property competitiveness.

Understanding the Patent Invalidation Trial

A. Definition and Purpose of a Patent Invalidation Trial

A patent invalidation trial (hereinafter "invalidation trial") is a quasi-judicial administrative proceeding in which the Intellectual Property Trial and Appeal Board (IPTAB) nullifies a registered patent if it is found to have grounds for invalidity as prescribed by law. The effect is typically retroactive, meaning the patent is treated as if it never existed from the date of its registration.

Although patents are granted after a rigorous examination by the Korean Intellectual Property Office (KIPO), some may be issued for inventions that do not meet patentability requirements due to prior art that was missed during the examination or other defects. These improperly granted patents can exercise exclusive rights beyond their legitimate scope, hindering industrial development and distorting fair competition.

The invalidation trial system is a vital mechanism for rectifying these weak patents after they have been registered. By providing an opportunity to contest a patent's validity even after its grant, the system enhances the reliability of the patent system and prevents problems arising from improper monopolies. Specifically, its purpose is to eliminate weak patents to block the unfair exercise of rights by patentees, protect the interests of third parties, and contribute to sound industrial development and a fair competitive order. This allows companies to pursue technological development freely without the threat of invalid patents and to secure their own freedom to operate by challenging the improper patents of others.

B. Legal Basis in the Korean Patent Act

The primary legal basis for invalidation trials is Article 133 of the Korean Patent Act. This article defines who can file a trial (standing of the petitioner), on what grounds invalidity can be claimed (grounds for invalidity), and the procedures for filing a petition.

• Standing to File (Who can file?):
  • Interested Party: As a rule, an interested party is a person whose rights or legal standing are, or are likely to be, directly and actually prejudiced by the existence of the patent. A typical example is a company that is manufacturing, selling, or preparing to sell a product related to the patented technology of a competitor. Notably, a landmark Supreme Court en banc decision (2017Hu2819) clarified that a patent licensee also has standing as an interested party to file an invalidation trial. This means a licensee can be a potential petitioner, a point IP managers must consider during contract negotiations and rights management.
  • Examiner: An examiner can file a petition as a representative of the public interest, though this is rare in practice.
  • Restriction on Petitioners: If the ground for invalidity is that the application was filed by a non-entitled person or in violation of joint application rules, only the rightfully entitled person can file the petition.
• Respondent (Who is the target?): The patentee of the target patent. If the patent is co-owned, all co-owners must be named as respondents.
• Retroactive Effect (What is the effect?): When a patent is confirmed as invalid through a trial, the patent right is, in principle, deemed to have never existed from the beginning. This powerful retroactive effect can nullify past infringement liability and may lead to the issue of refunding previously paid royalties (with exceptions for grounds of invalidity that arise later). This potent effect is what makes the invalidation trial a cornerstone of patent dispute resolution.

C. Importance for IP Managers

For an IP manager, the invalidation trial system is more than just a legal procedure. It is a strategic tool that directly impacts R&D direction, freedom-to-operate (FTO) for new product launches, responses to technology disputes with competitors, license negotiation strategies, and overall management of the corporate IP portfolio. Therefore, IP managers must have a precise understanding of the system's legal requirements and procedures and possess the insight to use it offensively or defensively in alignment with the company's business and technology plans.

Detailed Analysis of Grounds for Patent Invalidity

To file an invalidation trial, one must specifically allege and prove that the patent falls under one or more of the statutory grounds for invalidity listed in Article 133(1) of the Patent Act. A trial cannot be requested for any other reason. If a patent has multiple claims, a trial can be filed against each claim individually.

A. Main Substantive Grounds for Invalidity (Flaws in the Invention Itself)

• Lack of Novelty (related to Article 29(1)): This applies when the invention is identical to a prior art invention that was publicly known, publicly worked, published in a printed or online publication, or otherwise made available to the public in Korea or abroad before the patent application was filed. Novelty is assessed by directly comparing the claimed invention with a single prior art reference; combining multiple references is not considered.
• Lack of Inventive Step (related to Article 29(2)): This applies when a person having ordinary skill in the art (a "POSITA") to which the invention pertains could have easily conceived of the invention based on the prior art. This is the most frequently contested ground for invalidity in practice. Unlike novelty, it involves a normative judgment of whether the invention was "easy to create," making it more contentious. Inventive step is determined by comprehensively considering factors such as the invention's objective, the difficulty of its configuration, the motivation to combine prior art references, and the significance of its effects. A simple combination of known technologies, a mere modification, or the addition of a widely used technique is generally considered to lack an inventive step. While commercial success can be used as secondary evidence, it does not in itself establish an inventive step.
• Insufficiency of Description (related to Article 42): This applies when the patent specification fails to meet statutory requirements. The main types are:
  • Enablement Violation (Article 42(3)(1)): The description of the invention is insufficient for a POSITA to easily carry out (reproduce) the invention.
  • Written Support Violation (Article 42(4)(1)): The claims are not supported by the description of the invention.
  • Clarity Violation (Article 42(4)(2)): The claims are not stated clearly and concisely, making the scope of protection ambiguous. As the specification is the foundation of both the scope of rights and the disclosure of the technology, these requirements are strictly applied.

B. Other Main Grounds for Invalidation

• Violation of the First-to-File Principle (related to Article 36(1)-(3)).
• Application by a Non-Entitled Person (related to Articles 33(1) and 133(1)(2)).
• Violation of Joint Application Rules (related to Articles 44 and 133(1)(2)).
• Addition of New Matter via Amendment (related to Articles 47(2) and 133(1)(6)).
• Divisional/Converted Application Exceeds Scope of Original Application (related to Articles 52(1) and 133(1)(7), (8)).
• Violation of a Treaty (related to Article 133(1)(4), (5)).
• Patent Granted to a Person Without the Capacity to Hold Rights (related to Articles 25 and 133(1)(1), (4)).
• Other Grounds: As specified in each subparagraph of Article 133(1), such as inventions contrary to public order or morality (violation of Article 32).

Invalidation Trial Procedure at the IPTAB

An invalidation trial is conducted by the IPTAB, a specialized body within KIPO, and follows a strict, quasi-judicial process comparable to civil litigation.

A. Filing Stage

The process begins when an interested party or an examiner submits a petition for an invalidation trial to the President of the IPTAB. The petition must clearly state the petitioner/respondent, the case details, the requested relief (e.g., "The patent... shall be invalidated"), and the grounds for the request, including the supporting facts and evidence. A trial can be requested for all or only some of the claims, at any time during the patent's term or even after it has expired. The IPTAB first conducts a formality check and may request corrections before proceeding.

B. Respondent's (Patentee's) Response: Answer and Request for Correction

Once the petition passes the formality check, a copy is sent to the respondent (patentee), who is given a deadline to submit an answer. The patentee can use this opportunity to rebut the petitioner's claims.

A crucial defensive tool for the patentee is the Request for Correction (Article 133-2). Within the period for filing an answer, the patentee can file a request to correct defects in the patent specification or drawings. This can include narrowing the claims, correcting errors, or clarifying ambiguities. However, substantially broadening or altering the claims is not permitted. This is a critical defensive maneuver, and petitioners must anticipate and prepare for potential corrections. If the correction is accepted, the trial proceeds based on the amended patent.

C. Evidence Submission and Examination

Following the principle of party-led proceedings, both the petitioner and respondent must actively submit evidence (prior art documents, experimental data, expert opinions, etc.) to support their arguments. Evidence can also be submitted at the appellate stage before the Patent Court. The IPTAB panel may also examine evidence on its own initiative (ex officio).

D. Hearing Method: Written and Oral Hearings

The trial is conducted primarily through written examination of the submitted documents for efficiency. However, an oral hearing may be held if deemed necessary by the panel or requested by a party, where both sides present their arguments in person. The panel can also investigate grounds not raised by the parties (ex officio examination), but it must give the parties an opportunity to be heard on those grounds.

E. Trial Decision and Its Effects

Once the panel determines the examination is complete, it issues a trial decision.

• Decision to Grant: If the petition is well-founded: "Patent (or Claim X) is invalidated."
• Decision to Dismiss: If the petition is unfounded: "The petition for trial is dismissed."
• Decision to Reject: If the petition is non-compliant with legal requirements: "The petition for trial is rejected" (without a judgment on the merits).

The decision becomes final and binding if no appeal is filed within 30 days of receiving the decision. A confirmed decision to grant invalidation has a retroactive effect. Furthermore, once a decision is final, another invalidation trial cannot be requested based on the same facts and evidence (res judicata).

F. Appeal Procedure

A party dissatisfied with the IPTAB's decision can file an appeal to the Patent Court of Korea within 30 days. A subsequent appeal of the Patent Court's judgment can be made to the Supreme Court.

Strategic Considerations for IP Managers

A. Offensive Use: Securing FTO and Competitive Advantage

• Secure Freedom to Operate (FTO): Before launching a new product or developing a new technology, you can proactively file an invalidation trial to eliminate a competitor's blocking patent. This clears potential infringement risks and ensures a smooth market entry.
• Gain a Competitive Advantage: Invalidating a competitor's key technology patent can lower market entry barriers and relatively strengthen your company's technological position.
• Increase Licensing Negotiation Leverage: When negotiating a license, an analysis showing a high probability of the target patent's invalidity can be a powerful tool to lower royalty rates or secure more favorable terms.

B. Defensive Use: Countermeasure to Infringement Litigation

• Counterattack Against Infringement Claims: When faced with a warning letter or a patent infringement lawsuit, filing an invalidation trial is one of the most powerful defensive strategies. If the patent is invalidated retroactively, the basis for the infringement claim disappears entirely.
• Tactical Delay of Litigation: While an invalidation trial does not automatically stay an infringement suit, in practice, the court often adjusts the pace of the lawsuit to await the IPTAB's expert decision. Statistics show the IPTAB's decision often precedes the court's first-instance ruling.
• Use in Parallel with an Invalidity Defense in Court: A defendant in an infringement lawsuit can also argue that the patent is invalid (an "invalidity defense"). However, the definitive and expert judgment on validity rests with the IPTAB. Therefore, filing a separate invalidation trial in parallel with raising an invalidity defense in court is often more effective for obtaining an in-depth review and securing favorable evidence.

C. Relationship with Patent Infringement Litigation

Although they proceed in separate venues (IPTAB and the courts), patent infringement litigation and invalidation trials are closely intertwined.

• Parallel Proceedings: In a typical patent dispute, both proceedings run concurrently.
• De Facto Binding Effect of the Trial Decision: While not legally binding on the court, the court gives significant weight to the IPTAB's expert decision on patent validity. A decision of invalidity from the IPTAB is, in practice, often decisive for the outcome of the infringement suit. The IPTAB thus functions as the de facto first instance for validity.
• Validity as a Prerequisite: Patent infringement presupposes the existence of a valid patent. Therefore, the question of validity is a preliminary issue.

D. Linkage with Other Types of Trials

IP managers should understand the interplay between different types of trials, such as Scope Confirmation Trials (to determine if a product falls within the scope of a patent), Correction Trials (a standalone trial filed by a patentee to correct their patent), and the Patent Cancellation System (a simpler procedure where anyone can request cancellation within 6 months of a patent's grant).

Utilizing Evidence in Invalidation Trials

A. Main Types of Evidence

• Prior Art Documents: The most critical evidence for proving lack of novelty/inventive step. This includes patent publications, academic papers, technical books, product catalogs, website posts, and news articles published before the filing date.
• Expert Opinions: Written statements from experts (e.g., professors, researchers) providing their views on the technology, prior art, inventive step, or description deficiencies.
• Experimental Data: Reports proving or disproving an invention's configuration or effects. This is particularly crucial in the fields of chemistry, pharmaceuticals, and biotechnology.
• Online Evidence: The importance of online posts, articles, and videos is growing, but it is crucial to prove their publication date and the integrity of their content.

B. Points to Note for Evidence

Success hinges on securing and effectively presenting credible evidence. A comprehensive prior art search, extending beyond patent databases to non-patent literature, is essential. Evidence should be submitted with a clear explanation of how it logically connects to the grounds for invalidity being argued.

Key Issues and Arguments in Practice

A. Principles of Claim Construction

The interpretation of the patent claims is the starting point for any validity analysis. The claims are interpreted based on their objective meaning, but the specification and drawings can be consulted to understand ambiguous terms. This first step often sets the entire direction of the trial.

B. The Standard for Inventive Step

The battle over inventive step is often the fiercest. The petitioner will typically argue that the claimed invention is an obvious combination of multiple prior art references. The respondent (patentee) will counter that this combination constitutes improper hindsight bias, arguing there was no motivation to combine the references and that the invention produces unpredictable and remarkable effects.

Recent Trends and Practical Implications

IP managers must stay informed of the evolving legal landscape. Recent key developments include the Supreme Court's clarification of a licensee's standing to file trials, the increasing use of online evidence, and the IPTAB's periodic revision of its Trial Examination Guidelines.

Advice for IP Managers

• Proactive Risk Management: Regularly assess the potential weaknesses of your own patents and monitor the patent activities of competitors to manage risks preemptively.
• Strategic Use of Trials: View invalidation trials not just as a defensive shield but as an offensive tool to achieve business objectives.
• Strengthen Evidence Management: Build a systematic process for searching, securing, and managing evidence.
• Collaborate with Experts: Effective collaboration with internal and external legal and technical experts (patent attorneys, lawyers) is key to success.
• Continuous Learning: Stay updated on changes in laws, court precedents, and procedural practices.

Concluding Remarks

The Korean patent invalidation trial system is a complex but indispensable tool for maintaining the integrity of the patent system and fostering a healthy competitive environment. A deep understanding and skillful utilization of this system are essential capabilities for protecting a company's IP assets and succeeding in the age of technology competition.

At Pine IP Firm, we encourage IP managers to approach the invalidation system as a proactive, forward-looking instrument. Prepare in advance, set clear objectives, build your case on solid evidence, and collaborate effectively with experts.

If you have any questions or require expert assistance, please do not hesitate to contact us at Pine IP Firm. We stand ready to be your trusted partner in achieving your IP goals.