Engineering

When buyers specify FR4 High-Tg on an RFQ, they often do so because a datasheet or engineer told them to. Fewer understand why it behaves differently from standard FR4 — and why that difference matters when a board heats up under load, goes through lead-free soldering, or operates in a demanding environment. The answer lies not in the glass fibres or mineral fillers, but in the epoxy resin chemistry itself.