What are Staggered Microvias?

Staggered microvias are microvias whose position on each layer is not directly above or below another microvia i.e the position of each microvia on the corresponding layer is offset. Microvias are smaller than traditional vias and usually used in high-density boards as they take up less space. They are drilled using lasers.

The other type of microvia is called stacked microvias.

In a recent study conducted by IPC, they found that stacked microvias of 3 or more layer have a higher probability of failure when compared to staggered microvias. Though the overall failure numbers are very low, there is a marked difference between the failures of stacked microvias over staggered microvias. So when using microvias for more than 2 layers, the staggered configuration is recommended.