All 31 nets are routed with zero airwires, and the main DRC set is clean. I’m doing the final manufacturing/readability pass now, including silkscreen cleanup and component/production checks.
The PCB itself is complete and clean. The only manufacturing blocker left is BOM metadata: 32 generic resistors/capacitors lack manufacturer part numbers, so I’m assigning production-grade passive MPNs and then re-running the final checks.
Finished the PCB: compact 50 × 80 mm four-layer board, optimized placement, SiWG917 antenna keepout, thermally isolated SHT41, complete routing, cleaned silkscreen, and production MPNs for all passives.
0 airwires
0 dangling traces
0 DRC/manufacturing errors or warnings
All 46 components / 31 nets complete
Open item:
A non-specific board-validator message appeared after completion despite clean DRC and routing; it has been reported internally.
Technical Construction File — USB-C WiFi BLE TH Sensor
Status
Draft — schematic-stage regulatory file.
Applicable Regulations
FCC Part 15 intentional radiator / unintentional radiator
CE RED for EU radio equipment
ISED Canada if sold in Canada
UKCA if sold in the UK
RoHS/REACH for consumer production
Product Description
USB-C powered indoor consumer temperature/humidity sensor node using a Silicon Labs SiWG917 Wi-Fi/BLE module and Sensirion SHT41 digital T/RH sensor.
Wireless Technology Summary
Table
Module
MPN
Technology
Frequency Band
Antenna
Notes
U1
SIWG917Y111MGABAR
Wi-Fi 2.4 GHz 802.11 b/g/n/ax + BLE 5.4
2.4 GHz ISM
Integrated antenna variant
Must follow Silicon Labs integration/keepout guidance
Required Documentation Checklist
Product block diagram — included in Project Specification
Draft BOM from schematic — available in Flux BOM
RF integration notes — included below
Draft Declaration of Conformity — created in this file
User manual outline — included below
Final schematic PDF export
Final PCB layout/Gerbers after layout
Module certification grants and integration manual from Silicon Labs
EMC/RF test reports from accredited lab
Final product labels with FCC/CE/UKCA marking
RF Design Notes
U1 must be placed at a PCB edge with the integrated antenna facing outward.
Keep the antenna clearance void of copper, traces, vias, components, and metal on all layers.
Keep U3/L1 buck regulator switch node and inductor away from U1 antenna region.
Maintain solid ground under the module body where allowed by the module datasheet.
Do not change the module antenna or add metal/plastic in direct contact with the antenna without RF validation.
Draft Declaration of Conformity
We, [Company Name], declare that the product USB-C WiFi BLE TH Sensor is designed to conform to applicable FCC Part 15, CE RED, RoHS, and EMC requirements when manufactured and integrated according to the final approved schematic, PCB layout, BOM, RF module integration guide, and user manual.
Consumer USB-C powered environmental sensor node with Wi-Fi, BLE 5.x, digital temperature/humidity sensing, protected 5 V input, and a 3.3 V low-power MCU/sensor rail.
Properties
WiFi
USB-C
Consumer IoT
5
V
Bluetooth
Pricing & Availability
Distributor
Qty 1
Arrow
$4.12–$7.29
Digi-Key
$0.03
HQonline
$3.85–$3.95
LCSC
$6.01–$6.18
Mouser
$30.02
TME
$3.60
Verical
$5.15–$68.70
Controls
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