Sumitomo Chemical Subsidiary to Establish of a Joint Venture with Samsung Electro-Mechanics for the Glass Core Substrate Business
Jointly Promoting the Next-Generation Core Substrate Business for Advanced Semiconductor Packages

Jul. 2, 2026

Sumitomo Chemical today announced that its wholly owned Korean subsidiary, Dongwoo Fine-Chem Co., Ltd. (“Dongwoo Fine-Chem”), has signed a joint venture agreement with Samsung Electro-Mechanics Co., Ltd. (“Samsung Electro-Mechanics”) to establish a joint venture company (“the New Company”) that will engage in the business of glass core substrates for advanced semiconductor packages. The New Company is scheduled to be established in 2026, subject to the completion of necessary procedures, including approvals from the relevant authorities.

In recent years, driven by the growing adoption of generative AI, expanding data center investments, and rising demand for high-performance computing, semiconductors have been required to achieve even greater integration and lower power consumption. As a result, semiconductor package substrates are also needed in order to support further increases in size and density. This has led to glass core substrates garnering attention as a technology that supports next-generation semiconductor packages.

Glass core substrates are next-generation semiconductor package substrates with features such as excellent rigidity, dimensional stability, low warpage, and low thermal expansion, which contribute to larger package sizes, improved reliability, and higher-density wiring. In particular, AI-related semiconductors are expected to see even greater package enlargement and higher density going forward, and glass core substrates, which are a promising option well suited to these requirements, are expected to experience a full-scale market launch.

Dongwoo Fine-Chem has long cultivated glass handling technologies through the manufacturing of products using thin glass, operational know-how for automated equipment compatible with large-area glass substrates, and high-quality production technologies that meticulously control cleanliness and process management. By leveraging these process improvement capabilities, its analysis and evaluation infrastructure, existing facilities, and human resources it has cultivated up until now, Dongwoo Fine-Chem will be able to provide integrated support from the development and ramp-up of glass core substrates to their mass production.

Samsung Electro-Mechanics is a global leader that has long operated in the fields of advanced semiconductor package substrates and electronic components, and it specializes in substrate design and manufacturing technologies for high-layer-count, high-density wiring, and large packages. Samsung Electro-Mechanics possesses quality and reliability capabilities developed in high-performance fields such as AI servers, customer service cultivated through transactions with advanced semiconductor manufacturers, and commercialization expertise, including mass-production launches. It has also been working on the development and practical application of glass core substrate technology from an early stage.

The New Company will be established as a business for glass core substrates for advanced semiconductor packages, and will bring together the technologies and expertise of both companies. It is scheduled to establish a supply system by the second half of fiscal 2027. Following this, the New Company will gradually expand supply capacity and grow the glass core substrate business.

The Sumitomo Chemical Group positions ICT-related fields as one of its growth drivers and is working to expand its semiconductor materials business. So far, the Group has expanded its semiconductor front-end materials business, mainly centered on photoresists and semiconductor chemicals, to meet the growing demand for advanced semiconductors. In addition, for back-end businesses such as package materials, substrate materials, and next-generation process materials, the Group is steadily advancing development, launch, and sales growth by making the fullest use of its core technologies. Through the establishment of this joint venture, the Group will further strengthen its business foundation in the next-generation semiconductor package field. Through doing so, it will contribute to the development of the semiconductor industry and the achievement of a smart society by providing high-quality products and technologies.

Overview of the New Company (planned)

Company name	GlaSSEM (tentative name)
Head office Location	Pyeongtaek-si, Gyeonggi-do, Republic of Korea
Representative	Lee Dongwoo
Business description	Development, manufacturing, and sales of glass core substrates for advanced semiconductor packages
Share capital	KRW 482,100 million
Date of establishment	2026 (planned)
Shareholding structure	Samsung Electro-Mechanics 66%, Dongwoo Fine-Chem 34%

(Reference) Overview of the two companies investing in the New Company

Dongwoo Fine-Chem Co., Ltd.

Company name	Dongwoo Fine-Chem Co., Ltd.
Head office location	Pyeongtaek-si, Gyeonggi-do, Republic of Korea
Representative	Jong-chan LEE
Business description	Research, manufacturing, and sales of semiconductor processing chemicals, photoresists, optical functional films, touch-sensor panels, communication devices and materials, and other products
Share capital	KRW 293,227 million
Date of establishment	December 1991

Samsung Electro-Mechanics Co., Ltd.

Company name	Samsung Electro-Mechanics Co., Ltd.
Head office location	Suwon-si, Gyeonggi-do, Republic of Korea
Representative	Chang Duckhyun
Business description	Research, Manufacturing, and sales of electronic components, semiconductor package substrates, camera modules, and other products
Share capital	KRW 388,003 million
Date of establishment	November 1973

Contact

Sumitomo Chemical Co., Ltd.
Corporate Communications Dept.
https://www.sumitomo-chem.co.jp/english/contact/public/