muon

Minimal USB-C to JST-SH daughterboard PCBs

Currently in development; not finalized or tested.

Variants

Variant A (latest revision A2)

Narrow and wide variant

Variant B (latest revision B2)

Symmmetrical and rectangular variant

Features

• Physically compact
  • 31.50 x 10.00 mm for Variant A
  • 20.00 x 13.50 mm for Variant B
  • Balanced minimizing of dimensions with a focus on ease of implementation on the case-side
• Physically robust
  • 2x M2.5 screws for a balance between robustness, ease of manufacturing, user-friendliness, and physical compactness
  • 1.6mm PCB to counter cable torque and resist over-tensioned screw-in by users
• Minimal, practical implementation
  • Single-sided for easy assembly - whether at a factory or reflowing at home
  • Two-layer for affordable manufacturing
  • 3D printable solder paste stencil file included (0.2mm nozzle and line width, 0.08mm layer height)
  • Asymmetrical design with protruding USB port prevents accidental reverse installation by users
• Optimized for ease of case design
  • Straightforward, rational dimensions
  • Large USB connector overhang for case-side flexibility and robustness
  • Can be mounted component-side-up or component-side-down for prioritizing ease of servicing or physical compactness respectively
  • 3D models and example case-side implementation provided (see the References folders in the Var-A/Var-B directories)
  • Designed with aesthetics in mind to avoid detracting from case visuals
  • Example implementations can be CNC-machined with 2mm inner radius
• Proven circuitry and implementation based on the Unified Daughterboard series
  • ESD/overcurrent/overvoltage protection, single-path grounding of case via mounting screws
  • JST-SH connector with identical pinout to the Unified Daughterboard

Dimensions

Mounting screws are M2.5.
Only use flat screws - countersunk screws apply focused angled pressure on the screw holes and risk shattering the board apart.

Recommended max diameter for screw heads/standoffs/mounting points contacting the board is 5.00mm centered on the mounting holes.
Absolute max diameter is 6.0mm; ESD handling capabilities may be reduced when exceeding 5.00mm.

Variant A

Ends are roughly 5.00mm radius (slightly inset from a tangent arc for visual reasons).

Variant B

Corners are roughly 1.85mm radius (slightly inset from a tangent arc for visual reasons).

Pinout

Pinout is identical to the Unified Daughterboard series.
Only use a one-to-one cable (the same type used on the Unified Daughterboard JST-type boards; pin 1 of one end maps to pin 1 of the other end).