board.via_drill
a via's drill diameter on a net (metres, shown in mm)
What it is ¶
board.via_drill(net, mm) yields one row per net that has vias, giving the net’s MINIMUM via
drill diameter, held in metres and shown in mm. net is the net name (the join key to
ir.Net.name); mm is a number, so a query compares it with a unit (?d < 0.3mm). A net with several via sizes reports
only its smallest drill, not every via.
For hardware engineers ¶
On a net, the smallest drill is the most likely to fall below a fab’s minimum drill capability or to carry too little copper for the current through it. A review checks that number. 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 length, written with its unit.
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, reducing it to the minimum drill keyed by net. The relation reports the
minimum, the safety-relevant extreme, rather than one row per via. That keeps it 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
metres. The engine folds a query literal to the same SI base, and a cell is shown in millimetres.
Go projector ¶
boardFacts in stdlib/relations/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. It
returns a false ok when the net has no vias, and then no row is emitted. The nanometre minimum is
converted with nmToMM, shown as millimetres, and emitted as board.via_drill(net, mm) with the
numeric value populated in metres for comparison.
The board tier is EMPTY on a netlist-only design. Model.BoardNets() returns nothing unless the
design was loaded with board geometry (check.WithBoard, fed a .kicad_pcb or IPC-2581 board
sidecar). For a query this is silent by construction, so board.via_drill yields zero rows on any
design without board geometry. The datasheet tier behaves the same way without --params. An
empty answer 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 < 0.3mm => ?n, ?d
Write the threshold with its unit. A drill is held in metres and shown in millimetres, so a bare
0.3 would mean 0.3 m and every net would answer.
Both need a board-bearing design (a .kicad_pcb or an IPC-2581 file); on a netlist-only load they
return nothing.
Schematic ¶
