South Korea Faces Mounting Technology Leaks to China as Display Raids Renew Alarm

Display raids expose a wider industrial threat

Police raids at LG Display in Paju and Samsung Display in Asan have brought South Korea's struggle with industrial technology theft back into focus. Investigators suspect employees passed advanced display manufacturing knowledge to a Chinese company. Officials say the industrial technology security unit seized hundreds of photographs of internal process documents, production diagrams and laboratory notes.

As of October 25, 2025, the investigations form part of a wider pattern affecting semiconductors, displays and rechargeable batteries. Authorities recorded 27 overseas technology leak cases in 2024 and another eight in the first half of 2025, with most traced to Chinese recipients. Semiconductor processes accounted for nine of last year's cases, while display technology accounted for eight.

Data submitted to the Ministry of Trade, Industry and Energy show that 33 national core technologies and 105 industrial technologies leaked overseas between 2020 and June 2025. Estimated financial damage reached 23.27 trillion won. South Korea designates particularly sensitive capabilities as national core technologies because their loss can harm national security or have a substantial economic impact.

Executives warn that each breach weakens an innovation advantage built over decades, while Chinese competitors close remaining gaps faster than many expected. The consequences reach beyond individual factories. Display production supports smartphones, televisions and vehicle dashboards, while memory chips underpin phones, servers and other equipment.

Investigators describe a shift from cyber intrusions toward leaks assisted by insiders. Employees who understand a manufacturing process can select the settings, documents and practical instructions that matter most. For a rival, that knowledge can replace years of expensive experiments with a much shorter route to reliable production.

Why a display recipe can be worth years of research

OLED, QD OLED and micro OLED displays depend on complicated layers of materials and tightly controlled manufacturing steps. Deposition, the process of placing thin layers onto a surface, and encapsulation, which seals sensitive materials against damage, help determine how efficiently a panel works and how long it lasts.

Engineers refine deposition temperatures, mask alignment, carrier gas flow and proprietary light emitting material formulations through years of trial and error. Small changes can improve efficiency and resistance to burn in, the lasting marks that can appear when parts of a display age unevenly.

Factories closely guard their process windows, the ranges of settings within which production works reliably. Photographs of equipment control screens can therefore carry valuable information even without a complete technical manual. Internal documents may show which combinations have already succeeded and which approaches failed.

A competitor with those details can shorten testing, improve yields and reduce research costs. Yield means the share of manufactured products that meet the required standard. Higher yields allow a factory to sell more usable panels from the same production effort, affecting both prices and its ability to supply customers consistently.

The Samsung DRAM case and CXMT's advance

On October 1, 2025, prosecutors indicted three former Samsung Electronics employees over allegations that they used leaked DRAM manufacturing technology to help ChangXin Memory Technologies, the Chinese company known as CXMT. The case concerns Samsung's 18 nanometer DRAM process, developed at an estimated cost of 1.6 trillion won.

Investigators say the three obtained process files and practical manufacturing knowledge from two other former employees who had already been charged. They allegedly checked the information by dismantling Samsung modules, comparing test structures and conducting manufacturing trials until the process was ready.

CXMT announced in 2023 that it had become the first Chinese manufacturer to mass produce 18 nanometer DRAM chips. Prosecutors now connect that achievement to the alleged use of stolen Samsung knowledge. They estimate damage to Samsung at around 5 trillion won over the past year and expect losses to increase as the Chinese producer gains customers.

Prosecutors say the recruits were promised annual salaries of up to 3 billion won, three to five times their previous pay. Authorities are pursuing another former worker under an Interpol red notice for allegedly copying hundreds of steps in the DRAM manufacturing flow into notebooks.

Defense lawyers in technology leak cases have argued that some process information is publicly available or comes from earlier employment. Investigators point to internal materials and testing paths that they say match company documents. The charges describe alleged conduct, and the October 1 indictments are the prosecution step detailed in this case.

DRAM is the short term working memory that helps phones, servers and vehicles run applications. An 18 nanometer production node describes a class of feature sizes and design rules used to form memory cells and the connections between them.

Smaller features allow manufacturers to fit more bits of memory onto a wafer, the thin disc on which chips are made. That raises density and lowers the cost of each bit, but requires precise lithography, thin film deposition, patterning, etching and inspection. Lithography transfers patterns onto a wafer, while etching removes selected material to form the required structures.

A proven recipe brings those steps together. It improves yields, reduces defects and supports faster introduction of products such as DDR5 memory modules. South Korea treats this process knowledge as national core technology because it supports the country's competitiveness in memory manufacturing.

How the losses have accumulated

The estimated 23.27 trillion won in damage since 2020 reflects more than sales lost immediately after a leak. A rival can use stolen instructions to reach stable production faster, compressing years of research and supplier adjustments into a practical manufacturing guide.

Smartphone, television, data center and electric vehicle markets all reward reliable supply, competitive costs and the ability to produce in volume. Faster improvements at a competing factory can narrow the price and performance advantages that Korean companies spent years building.

The figures also show how concentrated recent cases have been. Semiconductor and display incidents together accounted for 17 of the 27 overseas technology leak cases recorded in 2024. Batteries and other industrial technologies are also within the wider exposure described by authorities.

The main dates show how investigations, manufacturing advances and concerns about sentencing have developed:

• 2020 to June 2025: Data submitted to the industry ministry recorded overseas leaks involving 33 national core technologies and 105 industrial technologies, with estimated damage of 23.27 trillion won.
• 2021: A study found that 87.8 percent of lower court cases ended in acquittals or suspended sentences.
• 2023: CXMT announced mass production of 18 nanometer DRAM, a milestone prosecutors now link to leaked Samsung knowledge.
• 2024: Authorities recorded 27 overseas technology leak cases, including nine involving semiconductor processes and eight involving displays.
• First half of 2025: Authorities recorded eight more overseas technology leak cases.
• October 1, 2025: Prosecutors indicted three former Samsung employees in the CXMT case.

Recruitment offers and the movement of manufacturing knowledge

Officials and engineers describe a recurring method. A small group of insiders gathers process documents, photographs of control settings, scrap wafers or rejected panels. Teams abroad then examine commercial products to check the leaked parameters. Trial production and repeated fixes fill remaining gaps.

Experienced process leaders are especially valuable because they know how separate production stages fit together. A veteran may move to a foreign foundry or supplier, followed within months by a small group of colleagues. Someone copies job instructions or takes photographs with a phone outside normal working hours.

Early recruits can spend weeks reverse engineering existing chips or panels, working backward from finished products to understand their construction. The team then uses the notes to adjust recipes and resolve defects. A new production line can stabilize much faster than one relying entirely on trial and error.

Police say most recent cases lead back to Chinese firms. Recruitment packages can include salaries several times previous pay, research budgets and promises of faster promotion if experienced staff bring knowledge that accelerates new production lines.

Prosecutors have documented offers reaching 3 billion won a year for senior engineers in memory and display manufacturing. Salary offers of 400 million won have also been reported for professors at the Korea Advanced Institute of Science and Technology. Chinese local governments have funded semiconductor ventures with budgets of several trillion won, creating demand for experienced people who can bring complete manufacturing playbooks.

A handful of process leaders can deliver yield improvements that make a new fabrication plant viable. Courts have also treated some suspects as potential flight risks where there are signs of continued contact with overseas teams.

Industry leaders press for stronger penalties

South Korea uses two main laws against industrial technology leaks. The Act on Prevention of Divulgence and Protection of Industrial Technology covers national core technologies and allows prison terms of up to 15 years or fines of up to 6.5 billion won. The Unfair Competition Prevention and Trade Secret Protection Act also allows imprisonment for up to 15 years.

Industry groups argue that actual sentences have often been much lighter than the legal maximums. A vice president at a partner company working with SK hynix received a prison sentence of one year and six months for leaking core chip technology. The study of lower court cases in 2021, in which 87.8 percent ended in acquittals or suspended sentences, has added to concerns about deterrence.

Courts have detained suspects on flight risk grounds in chip processing investigations. Prosecutors say they will continue pursuing people who attempt to export national core technologies or establish shadow teams abroad using stolen materials.

Judges have started weighing the combined value of an integrated manufacturing process rather than considering just one publicly available document. A production system can depend on how many individual settings and steps work together, making its practical value larger than any single instruction.

At the 16th Display Day event in Seoul, Samsung Display chief executive Yi Chung called for stronger government action against technology leakage.

Each technology leak causes tremendous losses, so we hope the government will take stronger action to help prevent them

At a National Assembly forum, Samsung Display executive vice president Park Jun-young said the display industry had experienced 21 leak cases over five years. He called for tougher penalties and safeguards for the most valuable processes.

It is urgent to strengthen effective penalties and establish strong safeguards for core national technologies.

Fuel cells, batteries and advanced manufacturing face risks

Former employees at a major automaker were jailed in a recent case for passing hydrogen fuel cell stack information to a Chinese company. A fuel cell stack is the central power producing assembly in a hydrogen vehicle, combining hydrogen and oxygen to generate electricity.

Its architecture, materials and control software determine durability and efficiency. Transferring that knowledge can give away the results of years of laboratory testing and work with suppliers.

Battery manufacturers and their partners face similar concerns over cathode chemistries, electrolyte additives and formation procedures. Formation refers to the controlled initial charging steps used to prepare a battery for operation. These choices help determine how long a battery lasts through repeated charging and use.

A competitor gaining access to those details could improve energy density and charging speed while avoiding expensive unsuccessful experiments. The targets reflect areas where South Korea has industrial strengths and where global demand is increasing.

Additive manufacturing, which builds parts by adding material in successive layers, has spread to aerospace parts and defense components in South Korea. Designs, printing settings and treatments after printing can help reproduce parts classified as national core technologies.

Contractors and small laboratories face particular vetting challenges because their security infrastructure is far less extensive than that of major chipmakers. Protecting a design therefore also means controlling access among the outside organizations that help turn it into a finished product.

Companies tighten access to documents and devices

Large semiconductor and display companies are introducing several layers of protection. Employees and contractors sign strict confidentiality agreements, and departing staff face restrictions on immediately joining direct competitors. Some employers also restrict external generative artificial intelligence services to prevent staff from accidentally uploading code or documents.

Security software on company devices records data movements and blocks unauthorized transfers. Sensitive tools require special authorization, while files leaving controlled folders can carry identifying watermarks and expire after a set period.

Memory manufacturers have added systems that record when process data is removed and automatically destroy files after a specified time. Phone cameras are restricted inside critical production areas. Some companies use monitoring applications on employee smartphones to disable photography in sensitive zones.

Automakers and shipyards appoint security officers to track device access, organize regular training and oversee export control compliance for design files. Together, these measures aim to limit how much information one insider can collect about a complete manufacturing flow.

Dividing the most sensitive knowledge among teams makes it harder for a single employee to leave with a complete recipe. Data loss prevention tools can flag large downloads, activity at unusual hours and mass printing. Exit interviews supported by forensic checks of laptops and cloud accounts can help identify copied material.

Vendors and joint venture partners also need screening and clear contractual rules on data use. Training based on real cases can show employees how small disclosures develop into theft affecting production. Clear channels for reporting concerns give staff a way to raise warnings before information spreads further.

Technology controls and the pressure to retain engineers

The United States is pressing allies to restrict the flow of advanced semiconductor technology to China. Agreements involving countries that export equipment are tightening access to leading lithography and inspection tools. South Korea is weighing the protection of its major manufacturers against the need to keep export markets open.

China is pursuing alternative routes as direct purchases become harder, including acquiring overseas assets, recruiting foreign talent and funding domestic versions of specialized tools. These routes place employee recruitment and the handling of manufacturing knowledge alongside equipment controls in the wider competition.

Policy options under discussion include higher fines linked to the value of stolen technologies, mandatory reporting of suspected leaks within specified periods and faster injunctions that freeze equipment when there is probable cause. Small and midsize businesses could receive grants for security upgrades and legal support. These are options under consideration.

Universities working on national core technologies can add compliance staff and monitor foreign recruitment more closely while preserving legitimate collaboration with overseas laboratories. Smaller companies also need protection suited to their resources, because sensitive work can pass through suppliers that lack the security budgets of large manufacturers.

Engineers may leave when they feel undervalued or unable to advance. Retention programs, bonuses linked to performance and clearer career routes for senior technical staff can reduce the attraction of overseas promises. An ethics culture that rewards responsible handling of confidential knowledge supports those efforts.

Prevention carries substantial costs, but repeated leaks carry larger ones. For Korean companies, the immediate task is to protect practical production knowledge while maintaining the people, suppliers and research partnerships that created it.

Key Points

• Police raided LG Display in Paju and Samsung Display in Asan over suspected technology transfers to a Chinese company.
• Authorities recorded 27 overseas technology leak cases in 2024 and eight in the first half of 2025, mostly linked to Chinese recipients.
• Prosecutors indicted three former Samsung employees on October 1 over alleged use of 18 nanometer DRAM knowledge to help CXMT.
• Estimated damage from overseas technology leaks between 2020 and June 2025 reached 23.27 trillion won.
• Legal penalties can reach 15 years in prison, while industry leaders are seeking stronger deterrence and safeguards.
• Risks extend to displays, batteries, hydrogen fuel cells and additive manufacturing.
• Companies are tightening access controls, monitoring data movement and strengthening checks on departing employees and outside partners.