Tests: fan-out stubs go outward past their pads; a plane pin gets its via

2026-09-29 09:53:05 -06:00
parent 2d686178af
commit 21c80d30f2
1 changed files with 78 additions and 0 deletions
@@ -0,0 +1,78 @@
+"""--fanout: fine-pitch pins get their way out committed before routing."""
+
+from __future__ import annotations
+
+from freeroute.board import build_board
+from freeroute.board.items import Trace, Via
+from freeroute.dsn import parse_dsn
+from freeroute.route.fanout import FanoutRules, plan_fanout
+from freeroute.route.pipeline import route_dsn_board_exact
+
+# a 12-pad package, 3 pads a side at 0.5 mm pitch, over a GND plane on In1;
+# pad 1 (left side, top) is GND, the rest are signals to far connector pads
+_SIDES = {
+    "L": [(-2000, y, 0) for y in (500, 0, -500)],
+    "R": [(2000, y, 0) for y in (500, 0, -500)],
+    "T": [(x, 2000, 90) for x in (-500, 0, 500)],
+    "B": [(x, -2000, 90) for x in (-500, 0, 500)],
+}
+_PADS = [p for side in "LRTB" for p in _SIDES[side]]
+
+
+def _dsn():
+    pins = "\n      ".join(
+        f"(pin {'padv' if r else 'padh'} {i + 1} {x} {y})" for i, (x, y, r) in enumerate(_PADS)
+    )
+    far = " ".join(f"(place C{i} {3000 + 2000 * (i % 5)} {-12000 - 2000 * (i // 5)} front 0)" for i in range(11))
+    nets = "(net GND (pins U1-1))\n    " + "\n    ".join(f"(net S{i} (pins U1-{i + 2} C{i}-1))" for i in range(11))
+    return f"""(pcb pkg (parser) (resolution um 10) (unit um)
+  (structure
+    (layer F.Cu (type signal)) (layer In1.Cu (type power)) (layer In2.Cu (type power))
+    (layer B.Cu (type signal))
+    (boundary (path pcb 0  -15000 15000  25000 15000  25000 -25000  -15000 -25000  -15000 15000))
+    (plane GND (polygon In1.Cu 0  -14500 14500  24500 14500  24500 -24500  -14500 -24500  -14500 14500))
+    (via "Via[0-3]_450:200_um") (rule (width 150) (clearance 150)))
+  (placement (component Q (place U1 0 0 front 0)) (component P {far}))
+  (library
+    (image Q
+      {pins})
+    (image P (pin padc 1 0 0))
+    (padstack padh (shape (rect F.Cu -400 -125 400 125)) (attach off))
+    (padstack padv (shape (rect F.Cu -125 -400 125 400)) (attach off))
+    (padstack padc (shape (rect F.Cu -500 -500 500 500)) (attach off))
+    (padstack "Via[0-3]_450:200_um" (shape (circle F.Cu 450)) (shape (circle B.Cu 450)) (attach off)))
+  (network {nets}))"""
+
+
+def _rules(dsn):
+    s = dsn.resolution.value
+    return FanoutRules(trace_width=150 * s, clearance=150 * s, via_half=225 * s, via_drill=200 * s,
+                       hole_to_hole=250 * s, edge_clearance=0, signal_layers=[0, 3],
+                       via_padstack="Via[0-3]_450:200_um")
+
+
+def test_every_pin_gets_a_stub_outward_past_its_pad():
+    dsn = parse_dsn(_dsn())
+    board = build_board(dsn)
+    items = plan_fanout(board, _rules(dsn))
+    stubs = [i for i in items if isinstance(i, Trace)]
+    assert len(stubs) == 12
+    for stub in stubs:
+        a, b = stub.corners
+        pin = next(p for p in board.get_pins() if p.location == a)
+        pad = pin.shape.bounding_box()
+        # outward: the stub ends further from the package centre, outside its pad
+        assert abs(b.x) + abs(b.y) > abs(a.x) + abs(a.y)
+        assert not (pad.ll.x <= b.x <= pad.ur.x and pad.ll.y <= b.y <= pad.ur.y)
+
+
+def test_a_plane_pin_gets_a_via_and_needs_no_route():
+    dsn = parse_dsn(_dsn())
+    board = build_board(dsn)
+    items = plan_fanout(board, _rules(dsn))
+    assert len([i for i in items if isinstance(i, Via)]) == 1
+    exact, _scale, _ = route_dsn_board_exact(dsn, resolution=2, fanout=True)
+    gnd = next(i + 1 for i, n in enumerate(dsn.nets) if n.name == "GND")
+    assert not any(f[0] == gnd for f in exact.result.failed)
+    assert exact.drc_clean
+    assert len(exact.result.vias.get(gnd, [])) == 1  # the fan-out's, written out