High density interconnections (HDI) are pivotal in modern electronics manufacturing and enable the development of devices that are both smaller and more complex. At the forefront of HDI technology are microvias, small but critical components that allow for the layer-to-layer electrical connections in multilayer circuit boards. Despite their benefits, microvias introduce substantial reliability challenges due to material behavior under heat, complex assembly processes and their intricate configurations. While many rules of thumb have guided the industry over time, innovation and deeper understanding of microvia reliability is now changing the way they are used and implemented into designs. Exploring challenges with microvias and insights into the latest strategies for enhancing their reliability through advanced material selection, design optimization and innovative testing methodologies results in better designs and more knowledgeable engineers.