What is a microvia?
According to the new definition within IPC-T-50M a microvia is a blind structure with a maximum aspect ratio of 1:1, terminating on a target land with a total depth of no more than 0.25mm measured from the structure’s capture land foil to the target land.
The IPC-6012 also defines the structure of a Microvia.
The Microvia is a blind structure with a maximum aspect ratio of 1:1 between hole diameter and depth, with a total depth of no more than 0.25 mm, when measured from the surface to the target pad or plane.
Typically NCAB considers the dielectric thickness between surface and reference pad to be 60 – 80um.
The diameter dimensions of the microvia have a range of 80-100 microns. The typical RATIO is between 0.6: 1 to 1: 1, ideal 0.8: 1