HDI boards are one of the most popular technologies in PCBs. HDI Boards are made up of blind vias, buried vias, and microvias that measure.006 inches or less. These boards have a higher level of circuitry density than traditional circuit board. There are six types of HDI boards: through vias with buried vias or through vias, two or three HDI layers with through vias, one or more passive substrates with no electrical connection; coreless construction using layer pair and alternate coreless constructions with layer pair. Shenzhen Unite... read full review »