HDI PCBs are modern circuit boards with high packing density, utilizing microvias, thin traces, and multiple electrically connected layers. They offer improved signal integrity, shorter signal paths, and a compact form factor, making them ideal for high-speed and high-frequency applications. They are especially used in smartphones, tablets, wearables, as well as in the automotive and medical technology industries due to their high reliability and small size. Advanced manufacturing methods like sequential lamination and laser drilling enable HDI PCBs to facilitate powerful and miniaturized electronic designs.