# CBM G1 — Mechanical Fit Report

Generated by `cad/validate_mechanical_stack.py` from the actual upstream
`Biocoin_v1.3.step`.

Overall geometric stack status: **PASS**

## Measured upstream geometry

- populated Biocoin envelope: **24.901 × 26.101 × 4.911 mm**
- PCB thickness in STEP: **0.960 mm**
- deepest bottom-side component below PCB: **1.888 mm**
- highest top-side component above PCB: **2.063 mm**
- Molex FPC body envelope: **3.600 × 11.700 × 1.895 mm**
- Raytac module envelope: **15.500 × 10.500 × 2.050 mm**

## Frozen axial stack

| Plane | Z (mm) |
| --- | ---: |
| cartridge hard-gold pad plane | 0.00 |
| interface daughterboard bottom | 2.24 |
| interface daughterboard top | 3.04 |
| Biocoin PCB bottom pad plane | 9.12 |
| populated Biocoin lowest point | 7.23 |
| populated Biocoin highest point | 12.14 |
| CP1240 battery bottom | 12.95 |
| CP1240 battery top | 16.95 |
| shell inner ceiling | 18.00 |
| shell exterior top | 19.00 |

## Clearance checks

| Result | Check | Actual | Requirement | Note |
| --- | --- | ---: | ---: | --- |
| PASS | Biocoin populated XY envelope inside shell | 2.46 mm | ≥ 1.50 mm | Conservative rectangular-envelope diagonal. |
| PASS | Daughterboard edge inside shell | 1.50 mm | ≥ 1.00 mm |  |
| PASS | LMP7721 package edge on daughterboard | 1.25 mm | ≥ 1.00 mm |  |
| PASS | Biocoin bottom component to daughterboard components | 2.59 mm | ≥ 0.50 mm | Excludes the four intentional spring-header interfaces. |
| PASS | Battery to highest Biocoin component | 0.81 mm | ≥ 0.80 mm |  |
| PASS | Battery to shell inner top | 1.05 mm | ≥ 0.80 mm |  |
| PASS | Battery radial edge to shell | 2.95 mm | ≥ 2.00 mm |  |
| PASS | Battery XY clearance from full Raytac module body | 2.31 mm | ≥ 2.00 mm | Conservative: clears the entire module, not only its antenna. |
| PASS | Cartridge connector compression | 0.30 mm | ≥ 0.30 mm | Full available stroke 0.61 mm. |
| PASS | Biocoin header compression | 0.70 mm | ≥ 0.69 mm | Full available stroke 1.397 mm. |
| PASS | Needle protrusion beyond adhesive skin plane | 0.78 mm | ≥ 0.70 mm |  |
| PASS | Latch retention design load | 17.65 N | ≥ 17.50 N | Connector preload ≈ 7.06 N. |

## Assembly hardware now represented

- four upstream-exact Biocoin docking headers:
  `855-22-010-10-001101` ×2 and `855-22-008-10-001101` ×2;
- one 12-position ultra-low-profile cartridge connector:
  `817-22-012-30-001101`, modeled at 2.24 mm working height;
- one 38 mm full daughterboard carrying six LMP7721 buffers, ADS124S08,
  connector footprints, guarded routing, and the cartridge connector;
- an offset, tabbed VARTA CP1240 in a shell-supported cradle, with a JST
  ACHR-02V-S / SACH-003G-P0.2 harness to the Biocoin battery header;
- four board-edge capture clips derived from the upstream Biocoin fixture;
- three cartridge snap hooks and a hard compression stop sized for at least
  **17.7 N** retention;
- a die-cut contact gasket and a separate enclosure seam gasket.

## What this report does not prove

- molded snap-hook fatigue or release force (requires FEA and cycle testing);
- gasket compression set and sweat-ingress performance;
- actual antenna efficiency in the final enclosure (requires VNA/OTA testing);
- connector coplanarity after real assembly;
- microneedle insertion, fracture, coating, and biological performance;
- vendor tolerances until production drawings and return CAD are received.