main module#
Test design — the minimum needed to prove the substrate builds.
The circuit is deliberately empty. Part 1’s acceptance is a verified substrate: that it type-checks, translates, and renders a correct cross-section. Placing components, routing, and applying these routing structures to real topologies is JS2 work, so nothing here reaches for a parts query or a route.
What this design does prove: the 41-entry stackup translates, all 12 via
structures register off the substrate walk, all 19 fabrication constraints are
present, and the four target routing structures resolve by impedance, with the
two neck structures beside them. The tests in
tests/test_js1_hdi_stackup.py check each of those against the fab CSV.