SNSPD PCB Slot
SIGNAL → VINRETURN → GNDJ1 → R5 (100 kΩ) → L1 (4.7 µH) → VINVOUT → J2, with R3 = 200 Ω to GNDVIN and VOUT, nominally 0.180 mm on L1, referenced to L2 GND.sub file is valid, but the built-in simulator cannot access uploaded include files.VIN and VOUT for 50 Ω.WARNING — PLACEHOLDER, NOT FABRICATION-QUALIFIED: The die-pad coordinates and real terminal map are unknown, and this geometry is based on explicit assumptions only. P1 and P2 now carry the provisional readout-model mapping described below; the other pads remain intentionally unconnected. Do not release for fabrication or bonding until every assumed value is replaced by detector-maker and bonding-lab approved data.
PRACTICE SNSPD geometry was replaced by a configurable ten-terminal bare-die wire-bond interface. The later readout correction preserved all mechanical geometry but provisionally connected P1 to VIN and P2 to GND for the uploaded four-terminal SPICE model. P3/P4 remain simulation-only NC, and P5-P10 remain intentional NC.(-13.0, -8.0) mm was translated upward by the smallest practical amount, 0.2 mm, because the proposed envelope bottom at y = -13.0 mm touched the top of the lower-left mounting-hole copper. The implemented interface center is (-13.0, -7.8) mm.Table
| Parameter | Assumed now | Replace with real value | Source needed |
|---|---|---|---|
| Bare-die outline | 6.0 × 6.0 mm | Approved nominal dimensions, tolerances, edge condition and datum | Detector mechanical drawing |
| Die outline layer | Top Overlay/documentation only | Approved assembly/documentation representation | Detector maker + assembly drawing standard |
| Copper die paddle | None | Add only if backside electrical and die-attach requirements demand it | Detector backside specification + bonding lab |
| Terminal count | 10 | Actual terminal/bond-pad count | Detector bond-pad drawing |
| Terminal arrangement | Two opposing PCB rows; five left, five right | Datum-based arrangement matching real die pads and tool access | Detector drawing + bonding-lab review |
| Left numbering | P1–P5, top-to-bottom | Real terminal names/polarity | Detector electrical pin map |
| Right numbering | P6–P10, bottom-to-top | Real terminal names/polarity | Detector electrical pin map |
| Perimeter numbering direction | Counterclockwise | Approved package/die numbering convention | Detector drawing |
| PCB bond-pad copper | 0.8 mm X × 0.4 mm Y, rectangle | Bonding-lab-approved land size, shape and finish | Bonding-lab process specification |
| Pad type/layer | Top Copper SMD, no drill, Top only | Approved substrate/layer construction | Bonding lab + PCB fabricator |
| Pad pitch | 1.0 mm in Y | Pitch derived from actual die-pad coordinates and fanout | Detector bond-pad coordinates |
| Die-edge to nearest PCB-pad copper gap | 0.4 mm | Datum-based distance supporting actual wire loops and attach fillet | Detector drawing + bonding lab |
| Solder-mask expansion | +0.05 mm | Approved mask opening or mask prohibition | Bonding lab + PCB fabricator |
| Solder-paste expansion | -0.25 mm | Verified zero-paste implementation for final land geometry | PCB fabricator and manufacturing export review |
| Paste aperture | Suppressed | Confirm no Top Paste aperture in final Gerber/ODB++ | Fabricator CAM review |
| Vias in bond pads | None | Add only if explicitly approved; normally keep bond lands via-free | Bonding lab + signal-integrity review |
| Electrical connection | Provisional: P1 = SPICE drain on VIN, P2 = SPICE source to GND, P3/P4 simulation-only NC, P5-P10 NC | Approved detector-to-readout net assignment | Detector pin map + circuit review |
| Nominal later bond-wire target | ≤1.5 mm | Actual maximum wire length and loop profile | Bonding-lab process window |
| Die-pad locations represented | No | Exact coordinates, sizes, openings and metallization | Detector bond-pad drawing |
| Working/tool envelope | 10 × 10 mm centered at (-13.0, -7.8) mm | Actual capillary/wedge, fixture and optical clearance | Bonding lab |
| Envelope enforcement | Documentation only; not enforced | Robust placement/copper/via keepout compatible with intended pads | Flux/tool capability + bonding-lab clearance |
| Pin-1 indication | Circle and PIN 1 label adjacent to P1 | Approved die orientation mark | Detector drawing |
| Placeholder position | Center (-13.0, -7.8) mm | Final datum-based location | Board mechanical and bonding fixture drawing |
-16.0…-10.0 mm, y = -10.8…-4.8 mm.-18.0…-8.0 mm, y = -12.8…-2.8 mm.-16.8 mm; y = -9.8, -8.8, -7.8, -6.8, -5.8 mm.-9.2 mm; y = -9.8, -8.8, -7.8, -6.8, -5.8 mm.0.8 × 0.4 mm, rectangular, Top Copper SMD, connectedLayers = Top, mask expansion +0.05 mm, paste expansion -0.25 mm.(0.8 mm row offset) − (0.4 mm pad half-width) = 0.4 mm on each side.1.0 mm in Y.0.2 mm above the top of MH2 mounting-hole copper at y = -13.0 mm.Text
TOP PIN 1→P1 [ ] [ ] P10 P2 [ ] [ ] P9 LEFT P3 [ ] DIE [ ] P8 RIGHT P4 [ ] 6×6 [ ] P7 P5 [ ] [ ] P6 BOTTOM
P1, P5, P6, P10, a dedicated PIN 1 text label, and a circular pin-1 marker.Table
| Terminal | Layout node UID | Center (mm) |
|---|---|---|
| P1 | 109f365d-5eeb-425d-834a-c91e10ad5692 | (-16.8, -5.8) |
| P2 | 8043fea9-baaa-4aac-a610-da281ee20bac | (-16.8, -6.8) |
| P3 | 7acd0432-a5ef-4b8d-8822-932b4b3bb990 | (-16.8, -7.8) |
| P4 | 93b15aed-3615-4a9e-8705-01e0ae5eeb6c | (-16.8, -8.8) |
| P5 | ae0c4c8a-3ab3-4411-b58c-77beb67ed3d1 | (-16.8, -9.8) |
| P6 | 9b59ca4b-7cea-4a5a-8109-f539cb0b5bae | (-9.2, -9.8) |
| P7 | add62d7c-2f5f-4c1e-82e9-d70ad21f4425 | (-9.2, -8.8) |
| P8 | 52ffe0c0-e85e-48d3-a05e-c639843f0b3f | (-9.2, -7.8) |
| P9 | 7209122e-60f9-41ec-86f6-bb48e553a002 | (-9.2, -6.8) |
| P10 | 9525f95f-5b6f-415d-8047-bdac0444a17b | (-9.2, -5.8) |
ASSUMED SNSPD Bare Die Outline 6x6mm.Top Overlay; never change it to copper unless the backside requirement is known and explicitly approved.SNSPD Pn Bond Pad).sizeX and sizeY, or recreate with geometry.size.padShape = rectangle, padHoleType = SMD, layer = Top Copper, and connectedLayers = Top unless approved data requires otherwise.row X = die edge ± (required copper gap + pad sizeX/2).solderMaskExpansion to the approved positive, zero or negative value.solderPasteMaskExpansion sufficiently negative that both resulting aperture dimensions are non-positive. For the current 0.8 × 0.4 mm pads, -0.25 mm contracts each edge and fully suppresses the limiting 0.4 mm dimension.SNSPD 10x10mm Working Envelope on Top Overlay for documentation.0.8 mm high and clear of copper, pads, holes and board edges.STOP: THE CURRENT P1/P2 ELECTRICAL ASSIGNMENT AND ALL TEN-PAD MECHANICAL ASSUMPTIONS ARE NOT FABRICATION-QUALIFIED.