PCB Placement Redesign

H

hanyyassa76

Execute the bottom/power PCB placement redesign now. Set board to 32 mm x 32 mm rounded-square with 8 mm corner radius and Standard 4 Layer stackup overrides: L1 Signal, L2 Ground Plane, L3 Power Plane, L4 Signal. Do not route. Preserve schematic components; do not delete. Ensure bottom-board components are included for PCB/BOM and top-board-only components are marked Exclude from PCB/BOM/Pick&Place. Place J7 exactly at X=+5.0 mm, Y=-17.6 mm, rotation 0°. Place U1/J2/RT1/U2/Q1/F1/J1/D1/PS1/L4/D2/D3/IC1/K1/J5/J6/D9/M1-M4/Q2-Q5/D4-D7 and local passives in the required functional groups. Run DRC/fit/routing feasibility checks, do not route, and update/create the project file 'Bottom Power PCB Placement Notes'. Keep final concise.

flux

I’ll apply the bottom/power PCB placement redesign, keep the schematic intact, exclude top-board-only parts from fabrication outputs, then run placement/fit/DRC feasibility checks without routing.

flux

I found the existing project files list and am applying the requested board geometry/stackup first, then I’ll use the project notes to classify bottom vs top-board-only parts.

flux

The board setup operation is hitting a platform-side “missing project document context” error, so I’m checking whether layout/document state is accessible before retrying with a lower-level edit path.

flux

Processing was stopped.
Here's a summary of what I was working on:
Troubleshooting tool issues
It looks like the tool is failing, which has me wondering if there's an active run. I might need to inspect the project metadata or check if the current project isn't in the right context. I see that the layout appears to be empty, which is odd. Perhaps there’s no layout document in context. I should report this, but maybe I can still proceed with mutating the layout component positions. It’s worth a try to read the docs for more insight.
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Schematic

Layout

3D View

Two-Board Redesign Plan
User-Requested Mechanical Architecture
  • 2-board stacked PCB architecture
  • Each board: 32 mm x 32 mm rounded square
  • Total stack height target: 10-11 mm including the stacked assembly
  • Side button moved off-board through a flex cable to the bottom PCB
  • Charging port should be centered on the inside/wrist-facing side of the watch, pointing toward the user's wrist/left side in the user's orientation example
  • Side button should be centered on the opposite outside edge of the watch, on the right side in the user's orientation example, so it is reachable from the outside when worn on the right hand
  • Preserve all components from the current design
  • Use the thinnest practical mezzanine interconnect available between boards
Existing Project Audit Snapshot
  • Current project contains one PCB layout only
  • Current board is a single 34 mm x 34 mm rounded rectangle, 4-layer stackup
  • Current single-board layout is already critically dense and flagged unroutable in multiple regions
  • Current routed state has extensive open routing / airwire issues
Functional Partition For Fresh Two-Board Stack
Top PCB
Place these functional groups on the top board:
  • nRF5340 MCU and its clocks, RF matching, antenna feed, and RF antenna
  • All sensor ICs and their local passives
    • ICM-42688-P IMU
    • MAX30102 optical PPG
    • MAX30205 temperature sensor
  • ADS1292R ECG front end and its analog support network
  • Safety / supervisor ICs
    • TPS3700
    • TPS3710
    • MAX6370
  • Required debug / programming access only if mechanically acceptable
Bottom PCB
Place these functional groups on the bottom board:
  • Battery connector / cell interface / NTC path
  • nPM1300 PMIC and battery protection network
  • TPS61041 boost converter and its feedback / output network
  • USB-C receptacle, ESD, fuse, CC network, and charge LED; place the USB-C receptacle centered on the inside/wrist-facing left edge of the watch/bottom PCB
  • Haptic motors and their driver / switching network
  • TLC555 stimulation / timing block and photorelay path unless ECG analog isolation requires final reassignment
  • Side button flex interface connector; route the side-button flex to the centered outside/right edge opposite the charging port
Interconnect Strategy
  • Preferred: ultra-low-height board-to-board mezzanine pair for power, battery, I2C/SPI/control, SWD, and selected sensor / actuator rails
  • Keep RF antenna entirely on the top board edge with no copper, battery, or connector shadowing below antenna region
  • Keep ECG electrode / sensitive analog paths away from boost converter, USB-C, and haptic current loops
  • Route side button through a dedicated flex-tail connector on the bottom PCB as requested
Charging Port and Button Orientation Rule
  • Charging connector type: USB-C 2.0 receptacle, schematic designator J1
  • Charging connector location for the bottom PCB: centered on the inside/wrist-facing left edge of the watch
  • Charging connector orientation: opening faces outward through the side wall on the inside/wrist side, so a cable plugs in from the wrist-side/left edge
  • Button location: centered on the outside/right edge of the watch, opposite the charging connector
  • Button connection method: side button via flex cable to the bottom PCB
  • Mechanical handoff wording: "Place the USB-C charging port centered on the inside/wrist-facing left side; place the side button centered on the opposite outside/right side."
Working Assumptions
  • The top board remains the RF / sensing board
  • The bottom board is the power / charging / actuator board
  • The existing project should preserve the electrical design intent and full component inventory
  • Total thickness budget allows two rigid PCBs plus mezzanine plus battery / mechanical stack, but final connector height must be verified against the enclosure
Platform Constraint Found During Audit
This project currently exposes only a single PCB layout object. I can resize and reorganize that one board, but I do not have a supported way in this project context to create a second independent PCB layout/board object inside the same design.
To complete the redesign faithfully, use one of these approaches:
  1. Preferred: split the product into two linked PCB projects (Top PCB project + Bottom PCB project) while keeping this project as the source architecture reference
  2. Fallback: keep one project and repurpose it for only one of the two boards, then clone/fork for the second board
What I Can Do Next Once You Choose the Path
  • Rework this project into the top board immediately and provide the bottom-board partition as the handoff baseline
  • Or, if you prefer, I can continue by documenting the exact component-to-board assignment list for every major part before the project split

  • User-Requested Mechanical Architecture

  • Existing Project Audit Snapshot

  • Functional Partition For Fresh Two-Board Stack

  • Top PCB

  • Bottom PCB

  • Interconnect Strategy

  • Charging Port and Button Orientation Rule

  • Working Assumptions

  • Platform Constraint Found During Audit

  • Recommended Next Execution Path

  • What I Can Do Next Once You Choose the Path