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