Add DRC check: vias too close to pads

index.ts

@@ -5,6 +5,7 @@ export { checkViasOffBoard } from "./lib/check-pcb-components-out-of-board/check
 export { checkPcbComponentsOutOfBoard } from "./lib/check-pcb-components-out-of-board/checkPcbComponentsOutOfBoard"
 export { checkSameNetViaSpacing } from "./lib/check-same-net-via-spacing"
 export { checkDifferentNetViaSpacing } from "./lib/check-different-net-via-spacing"
+export { checkViaToPadSpacing } from "./lib/check-via-to-pad-spacing"
 export { checkSourceTracesHavePcbTraces } from "./lib/check-source-traces-have-pcb-traces"
 export { checkPcbTracesOutOfBoard } from "./lib/check-trace-out-of-board/checkTraceOutOfBoard"
 export { checkPcbComponentOverlap } from "./lib/check-pcb-components-overlap/checkPcbComponentOverlap"

lib/check-via-to-pad-spacing.ts

@@ -0,0 +1,207 @@
+import type {
+  AnyCircuitElement,
+  PcbSmtPad,
+  PcbVia,
+  PcbViaClearanceError,
+} from "circuit-json"
+import { getReadableNameForElement } from "@tscircuit/circuit-json-util"
+import { cju } from "@tscircuit/circuit-json-util"
+import { DEFAULT_VIA_TO_PAD_MARGIN, EPSILON } from "lib/drc-defaults"
+import { getLayersOfPcbElement } from "lib/util/getLayersOfPcbElement"
+import type { Collidable } from "lib/check-each-pcb-trace-non-overlapping/getCollidableBounds"
+
+/**
+ * Compute the minimum edge-to-edge gap between a via (circle) and a pad.
+ *
+ * Via is treated as a circle with radius = outer_diameter / 2.
+ * Pad shapes handled: rect, circle, pill, rotated_rect, rotated_pill.
+ * Polygon pads fall back to a bounding-box approximation.
+ */
+function viaToSmtPadGap(via: PcbVia, pad: PcbSmtPad): number {
+  const viaRadius = via.outer_diameter / 2
+
+  if (pad.shape === "circle") {
+    const dist = Math.hypot(via.x - pad.x, via.y - pad.y)
+    return dist - viaRadius - pad.radius
+  }
+
+  if (pad.shape === "rect") {
+    return rectToCircleGap(
+      pad.x,
+      pad.y,
+      pad.width,
+      pad.height,
+      via.x,
+      via.y,
+      viaRadius,
+    )
+  }
+
+  if (pad.shape === "rotated_rect") {
+    return rotatedRectToCircleGap(
+      pad.x,
+      pad.y,
+      pad.width,
+      pad.height,
+      pad.ccw_rotation,
+      via.x,
+      via.y,
+      viaRadius,
+    )
+  }
+
+  if (pad.shape === "pill") {
+    // A pill is a rect with semicircular ends. Treat as a rect-to-circle
+    // distance, then subtract the pill's corner radius.
+    const innerWidth = pad.width - 2 * pad.radius
+    const innerHeight = pad.height - 2 * pad.radius
+    const gap = rectToCircleGap(
+      pad.x,
+      pad.y,
+      Math.max(innerWidth, 0),
+      Math.max(innerHeight, 0),
+      via.x,
+      via.y,
+      viaRadius + pad.radius,
+    )
+    return gap
+  }
+
+  if (pad.shape === "rotated_pill") {
+    const innerWidth = pad.width - 2 * pad.radius
+    const innerHeight = pad.height - 2 * pad.radius
+    const gap = rotatedRectToCircleGap(
+      pad.x,
+      pad.y,
+      Math.max(innerWidth, 0),
+      Math.max(innerHeight, 0),
+      pad.ccw_rotation,
+      via.x,
+      via.y,
+      viaRadius + pad.radius,
+    )
+    return gap
+  }
+
+  // Polygon — bounding box fallback
+  if (pad.shape === "polygon" && pad.points?.length) {
+    let minX = Infinity
+    let maxX = -Infinity
+    let minY = Infinity
+    let maxY = -Infinity
+    for (const p of pad.points) {
+      if (p.x < minX) minX = p.x
+      if (p.x > maxX) maxX = p.x
+      if (p.y < minY) minY = p.y
+      if (p.y > maxY) maxY = p.y
+    }
+    const cx = (minX + maxX) / 2
+    const cy = (minY + maxY) / 2
+    const w = maxX - minX
+    const h = maxY - minY
+    return rectToCircleGap(cx, cy, w, h, via.x, via.y, viaRadius)
+  }
+
+  // Unknown shape — return large gap so no false positive
+  return Number.POSITIVE_INFINITY
+}
+
+/**
+ * Minimum gap between an axis-aligned rectangle (center rx, ry, dimensions w x h)
+ * and a circle (center cx, cy, radius cr).
+ */
+function rectToCircleGap(
+  rx: number,
+  ry: number,
+  w: number,
+  h: number,
+  cx: number,
+  cy: number,
+  cr: number,
+): number {
+  const halfW = w / 2
+  const halfH = h / 2
+  // Nearest point on rect to circle center
+  const nearestX = Math.max(rx - halfW, Math.min(cx, rx + halfW))
+  const nearestY = Math.max(ry - halfH, Math.min(cy, ry + halfH))
+  const dist = Math.hypot(cx - nearestX, cy - nearestY)
+  return dist - cr
+}
+
+/**
+ * Gap between a rotated rectangle and a circle.
+ * We rotate the circle center into the rectangle's local frame, then
+ * use the axis-aligned rect-to-circle formula.
+ */
+function rotatedRectToCircleGap(
+  rx: number,
+  ry: number,
+  w: number,
+  h: number,
+  ccwRotation: number,
+  cx: number,
+  cy: number,
+  cr: number,
+): number {
+  // Translate circle center relative to rect center
+  const dx = cx - rx
+  const dy = cy - ry
+  // Rotate into rect-local frame (negate the CCW angle)
+  const cos = Math.cos(-ccwRotation)
+  const sin = Math.sin(-ccwRotation)
+  const localX = dx * cos - dy * sin
+  const localY = dx * sin + dy * cos
+  return rectToCircleGap(0, 0, w, h, localX, localY, cr)
+}
+
+function doLayersOverlap(layersA: string[], layersB: string[]): boolean {
+  if (layersA.length === 0 || layersB.length === 0) return true
+  return layersA.some((l) => layersB.includes(l))
+}
+
+export function checkViaToPadSpacing(
+  circuitJson: AnyCircuitElement[],
+  { minSpacing = DEFAULT_VIA_TO_PAD_MARGIN }: { minSpacing?: number } = {},
+): PcbViaClearanceError[] {
+  const vias = circuitJson.filter((el) => el.type === "pcb_via") as PcbVia[]
+  const pads = cju(circuitJson).pcb_smtpad.list() as PcbSmtPad[]
+  if (vias.length === 0 || pads.length === 0) return []
+
+  const errors: PcbViaClearanceError[] = []
+  const reported = new Set<string>()
+
+  for (const via of vias) {
+    const viaLayers = getLayersOfPcbElement(via as unknown as Collidable)
+
+    for (const pad of pads) {
+      const padLayers = getLayersOfPcbElement(pad as unknown as Collidable)
+      if (!doLayersOverlap(viaLayers, padLayers)) continue
+
+      const gap = viaToSmtPadGap(via, pad)
+      if (gap + EPSILON >= minSpacing) continue
+
+      const pairId = [via.pcb_via_id, pad.pcb_smtpad_id].sort().join("_")
+      if (reported.has(pairId)) continue
+      reported.add(pairId)
+
+      const viaName = getReadableNameForElement(circuitJson, via.pcb_via_id)
+      const padName = getReadableNameForElement(circuitJson, pad.pcb_smtpad_id)
+
+      errors.push({
+        type: "pcb_via_clearance_error",
+        pcb_error_id: `via_to_pad_close_${pairId}`,
+        message: `Via ${viaName} is too close to pad ${padName} (gap: ${gap.toFixed(3)}mm, min: ${minSpacing}mm)`,
+        error_type: "pcb_via_clearance_error",
+        pcb_via_ids: [via.pcb_via_id],
+        minimum_clearance: minSpacing,
+        actual_clearance: gap,
+        pcb_center: {
+          x: (via.x + pad.x) / 2,
+          y: (via.y + pad.y) / 2,
+        },
+      })
+    }
+  }
+
+  return errors
+}

lib/drc-defaults.ts

@@ -5,5 +5,6 @@ export const DEFAULT_VIA_BOARD_MARGIN = 0.3
 
 export const DEFAULT_SAME_NET_VIA_MARGIN = 0.2
 export const DEFAULT_DIFFERENT_NET_VIA_MARGIN = 0.3
+export const DEFAULT_VIA_TO_PAD_MARGIN = 0.2
 
 export const EPSILON = 0.005

lib/run-all-checks.ts

@@ -12,6 +12,7 @@ import { checkPinMustBeConnected } from "./check-pin-must-be-connected"
 import { checkNoGroundPinDefined } from "./check-no-ground-pin-defined"
 import { checkNoPowerPinDefined } from "./check-no-power-pin-defined"
 import { checkSameNetViaSpacing } from "./check-same-net-via-spacing"
+import { checkViaToPadSpacing } from "./check-via-to-pad-spacing"
 import { checkSourceTracesHavePcbTraces } from "./check-source-traces-have-pcb-traces"
 import { checkPcbTracesOutOfBoard } from "./check-trace-out-of-board/checkTraceOutOfBoard"
 import { checkTracesAreContiguous } from "./check-traces-are-contiguous/check-traces-are-contiguous"
@@ -47,6 +48,7 @@ export async function runAllRoutingChecks(circuitJson: AnyCircuitElement[]) {
     ...checkEachPcbTraceNonOverlapping(circuitJson),
     ...checkSameNetViaSpacing(circuitJson),
     ...checkDifferentNetViaSpacing(circuitJson),
+    ...checkViaToPadSpacing(circuitJson),
     // ...checkTracesAreContiguous(circuitJson),
     ...checkPcbTracesOutOfBoard(circuitJson),
   ]