board.via_drill
a via's drill diameter on a net (millimetres)
What it is ¶
board.via_drill(net, mm) yields one row per net that has vias, giving the net’s MINIMUM via
drill diameter in millimetres. net is the net name (the join key to ir.Net.name); mm is a
number, so a query can compare it directly (?d < 0.3). A net with several via sizes reports
only its smallest drill, not every via.
For hardware engineers ¶
The smallest drill on a net is the one most likely to be below a fab’s minimum drill capability or to carry too little copper for the current through it, so that is the number a review checks. Query this to find nets with vias drilled under a house minimum, or to confirm a high-current net does not route through an undersized via. The value is the physical drill diameter, so the threshold you compare against is a real millimetre figure.
For software engineers ¶
The routed net carries a set of vias, each with a drill diameter. board.via_drill is an
aggregate projection over that set: a reduce to the minimum drill, keyed by net. Reporting the
minimum (the safety-relevant extreme) rather than one row per via keeps the relation a compact
per-net answer rather than a full via dump. Rows are 1:1 with nets that have at least one via; a
net with tracks but no vias contributes no row. The stored unit is nanometres; the projector
converts to millimetres so a query reads a natural threshold.
Go projector ¶
boardFacts in check/facts.go walks Model.BoardNets() and, for each net, calls the helper
minViaDrillNm(bn.Vias), which returns the smallest Drill across the net’s vias (and a false
ok when the net has no vias, in which case no row is emitted). The nanometre minimum is converted
with nmToMM and emitted as board.via_drill(net, mm) with the numeric value populated for
comparison.
The board tier is EMPTY on a netlist-only design. Model.BoardNets() returns nothing unless the
design was loaded with board geometry (NewModelWithBoard, fed a .kicad_pcb or IPC-2581 board
sidecar). For a query this is silent-by-construction: board.via_drill yields zero rows on any
design without board geometry, the same posture the datasheet tier takes without --params. A
query returning nothing does not mean every via is large; it can mean the design carries no board
at all.
Datalog ¶
Every net and its minimum via drill:
board.via_drill(?n, ?d) => ?n, ?d
Nets with a via drilled below 0.3 mm:
board.via_drill(?n, ?d), ?d < 0.3 => ?n, ?d
Both need a board-bearing design (a .kicad_pcb or an IPC-2581 file); on a netlist-only load they
return nothing.
Schematic ¶
