Insights

Will Glass Substrates Replace PCBs? Three Things the Industry Should Understand in the AI Advanced-Packaging Era

As AI, high-performance computing (HPC), and multi-die integration continue to drive interconnect density upward, glass substrates have become an important topic in advanced packaging. The market, however, is also filled with claims that can easily create confusion—for example, that glass will soon replace conventional PCBs, that certain AI processors have already moved entirely to glass, or that a specific year will mark the beginning of immediate mass adoption. For PCB manufacturers, the more useful questions are what glass substrates are designed to replace, which engineering problems they address, and how they may change customer requirements. The short answer is that glass substrates are not expected to directly replace conventional FR-4 multilayer PCBs in the near term. Their primary target is the organic core substrate and selected interposer functions inside advanced semiconductor packages. This is a different layer from server motherboards, control boards, and conventional HDI PCBs.