A Korean company has pulled off a world-class breakthrough in glass-substrate manufacturing, a key process for next-generation semiconductor packaging.
The Viacore Consortium announced on July 9 that it had filed a PCT patent with the Japan Patent Office covering the entire process for Through-Glass Vias (TGV) -- from pretreatment all the way through metallization. The consortium groups Korean semiconductor startup Viacore with Japan's Daiichi and a major Japanese semiconductor-materials firm.
The patent covers a “glass substrate structure incorporating TGV.” Viacore developed the full direct-plating process, while the Japanese materials giant developed the key material for forming the intermediate layer -- the two sides split the patent 50-50. As of July, Viacore is also filing the same patent in four other countries: the US, Korea, China, and Taiwan. Simply filing under the Patent Cooperation Treaty (PCT) secures a year of protection, locking in first-mover status while the full applications proceed.
The core innovation in Viacore's direct-plating process is that it skips the sputtering step traditionally done via physical vapor deposition (PVD). Instead, it uses a specialized layer structure that builds chemical bonding and stress relief in stages at the interface between the glass substrate and the metal plating. Applied evenly even down inside the microscopic through-glass vias, this prevents delamination between dissimilar materials while securing adhesion, conductivity, and high-frequency performance all at once.
That matters because the high-vacuum PVD chambers used in conventional glass-substrate plating cost roughly 10 billion won -- about $6.6 million -- apiece. By eliminating that step entirely, Viacore sharply cuts capital equipment costs and simplifies line construction. Because the process runs largely at room temperature, it also minimizes the physical stress placed on the glass, which the company says boosts mass-production yield -- while cutting down on environmental impact as well.
The glass-substrate market is emerging as a critical technology for next-generation chip packaging, driven by surging demand for AI accelerators and high-bandwidth memory (HBM). According to market researcher SEMI, the glass-substrate market is projected to grow at a compound annual rate of 67.2% between 2028 and 2040.
Viacore has spent the past four years developing sputtering-free metallization with local partners including Japan's Daiichi. This year, the company is in active working-level talks with major partners in Korea, China, and Japan to bring the process into production. Those efforts are expected to accelerate once its pilot line in Ansan, Gyeonggi Province, comes online in the third quarter.
Follow-up development is also underway to push process yield to 100%. Viacore plans to work with laser specialist AccuLaser this year to develop a repair process and equipment that eliminates defects at the root during intermediate-layer formation.
“Our goal is to be the first to bring direct-plating to production in Korea and lead the push toward a global standard for glass-substrate processing,” a Viacore representative said. “We're currently running reliability and sample testing with major domestic companies, and we'll also respond to collaboration requests from Greater China.”
