PCB blind holes and buried holes is how to produce?

Through-hole can be the various layers of a compression, and then drill holes, plating on the line.

Blind and buried holes require a special process, there are several kinds: mechanical depth drilling method; sequential lamination method; HDI lamination method.

The sequential lamination method, for example:

For example, if there is a buried hole between layer 2 and layer 3, the etched layer 2 and layer 3 are pressed together, then drilled and plated, and then pressed together with layer 1 and layer 4, the buried hole is made.

For example, if there is a blind hole between layer 1 and layer 2, the etched layer 1 and layer 2 are pressed together, then drilled and plated, then pressed together with layer 3 and layer 4 to make a blind hole.

Try to avoid overlapping blind hole design. If you need a blind hole design, you will need to add layers of HDI, one by one, by laser drilling.