Discuss tolerances with fabricators

Problem environment

Fine pitch and challenging BGA designs lead to tolerance problems with pin to pin pitch and track to via clearance. Some fabricators are unable to provide the needed level of service.

Steps to reproduce

1. Inspect design rules in the layout
2. Generate and upload gerber files
3. Seek dialog and assurance from more than one fabricator

Expected result

Compare answers and consider guidance from the fabricators.

Actual result

Neither answers nor guidance has been obtained.

Workaround

Seek advice from online sources like KiCAD and Eevblog forums.

Severity level

This is medium priority because project deliverables could eventually fail due to advanced tolerance levels..

Tolerances are documented in dscomm.pro:

MinTrackWidth=0.09
MinViaDiameter=0.356
MinViaDrill=0.2
<and-so-on>

…which roughly correspond with HDI fabrication technology standards, and is accordingly expensive.