Independent Engineering Review of Completed 4-Layer KiCad PCB — ESP32 / LiPo / Haptic Device Ended

Project description

I am seeking an experienced electrical / PCB engineer to perform an independent technical review of a completed Rev A PCB design prior to fabrication.

The PCB has already been fully designed, routed, DFM-cleaned, and packaged for engineering review in KiCad. This project is not for new PCB design or layout.

The purpose of the engagement is to independently validate the design and identify any electrical, layout, signal-integrity, power, grounding, RF, or manufacturability issues that should be corrected before prototype fabrication.
The product is a compact battery-powered haptic module for medical-training applications. It uses an LRA actuator to create a physically palpable simulated pulse.

PCB overview
- 27 × 30 mm
- 4 layers
- 1.0 mm nominal thickness
- All components mounted on the top side
- KiCad native source
- Fully routed
- ERC: clean
- DRC: clean
- Zero unrouted connections
- DFM/silkscreen cleanup complete

Main components
- ESP32-C3-MINI-1U-N4X
- DRV2605L
- TPS63031
- BQ25100
- ~100 mAh protected 1S LiPo
- External FPC 2.4 GHz antenna
- External wired LRA
- Battery-voltage sensing
- Programming and diagnostic test pads

Requested review

Please independently review:
- overall schematic architecture
- component-selection suitability
- datasheet compliance
- power distribution
- TPS63031 switching regulator implementation and layout
- BQ25100 charger implementation
- fine-pitch 0.4 mm DSBGA footprint and routing
- ESP32-C3 power, grounding, and RF/antenna implementation
- DRV2605L / LRA implementation
- decoupling and capacitor selection
- ground-plane and return-current behavior
- USB differential-pair routing
- battery ADC noise sensitivity
- trace widths and via sizes
- 4-layer stackup assumptions
- solder mask / paste / stencil considerations
- assembly/manufacturing risks
- general DFM / DFA
- likely bring-up failure points

There are several known unresolved manufacturing qualifications already documented for the reviewer.

Deliverables

Please provide:
- written design-review findings
- clear identification of any must-fix issues before fabrication
- recommended but non-critical improvements
- optional refinements
- explicit confirmation where existing implementation appears acceptable
- annotated screenshots / KiCad notes where useful
- one review call or written walkthrough of findings

I am specifically looking for independent validation, not a complete redesign unless a genuine defect requires it.

Provided review package
Shortlisted candidates will receive a complete organized engineering package containing:
- native KiCad project
- schematic PDF
- PCB layer/review images
- ERC and DRC verification
- datasheets
- engineering-review brief
- design-history documentation
- known open items and manufacturing qualifications

Preferred experience
Strong candidates should have practical experience in several of the following:
- KiCad
- compact embedded electronics
- 4-layer boards
- switch-mode power
- battery charging
- ESP32 / BLE / RF
- fine-pitch BGA/DSBGA
- PCB assembly / DFM / DFA
- JLCPCB, PCBWay, or similar PCBA suppliers
- prototype bring-up and debugging

Budget
Target fixed budget: $300–500
Because the board is already complete and well-documented, this engagement is intended to be a focused independent review rather than a design-from-scratch effort.

Please provide:
- your fixed-price quote
- estimated engineering hours
- one or two examples of comparable PCB work
- a short explanation of how you would approach the review

Screening questions
1. How many years have you worked professionally in embedded hardware / PCB design?
2. Have you personally reviewed or designed 0.4 mm-pitch BGA or DSBGA layouts?
3. What experience do you have with buck/boost/buck-boost converter PCB layout?
4. What experience do you have with ESP32/BLE/RF hardware?
5. Have you taken compact multilayer designs through real PCBA production?
6. Are you comfortable reviewing an existing design without unnecessarily rebuilding it?
7. What would you consider the highest-risk areas of this type of board?

No medical-regulatory certification work is requested at this stage. This is prototype design validation before fabrication.

NDA available if appropriate. read less