Flexible PCB Design Review

flux

7:04

Evaluating user instructions.

Running design review.

Analyzing the PCB layout.

Optimizing component placement.

Considering placement modifications.

Inspecting the board layout.

Evaluating corridor layout.

Evaluating overlaps and rotations.

Analyzing height and overlaps.

Considering C9/C10 and Y2.

Considering layout adjustments.

Adjusting component positions.

Addressing connector placement.

Considering connector types.

Evaluating current spacing.

Figuring out a move.

Evaluating movement coordinates.

Verifying conditions.

Running design review.

Analyzing the PCB layout.

I continued the cleanup around U4/U5.
What changed
  • Pushed the PN7160 block further into the upper-left and kept its clock/support parts tight:
    • U4 now around (-31.7, 21.2) mm
    • Y2 around (-30.3, 13.0) mm
    • C9/C10 around (-34.2, 16.2) mm and (-37.2, 16.2) mm
    • C8 around (-32.0, 26.0) mm
  • Pushed the STM32 block further to the right:
    • U5 now around (33.5, 2.2) mm
  • Kept the edge interfaces in place:
    • J1/J2 along the bottom area
    • J3 on the left side
Result
  • The center routing corridor is more open now.
  • Component spacing is still comfortable on the card; the board remains low density and all parts still fit easily on the top side.
  • The card outline and 2-layer setup remain unchanged.
What did not clear yet
The remaining problems are still the same category:
  • overlapping copper around U4 and U5
  • many unrouted airwires
So this confirms the blocker is not mainly placement anymore. It’s now mostly:
  1. footprint/copper geometry around U4/U5, and/or
  2. unrouted traces in that hotspot region.
Thickness status
Your planned card thickness is still preserved as the manufacturing target:
  • intended flex build remains documented as:
    • 50 µm PI core
    • 18 µm copper/side
    • 25 µm coverlay/side
    • 0.2 mm local FR4 stiffeners only where needed
  • and the final 0.70–0.76 mm laminated card thickness is still the target for fab/lamination, not the live Flux rigid stackup model.
Best next step
The next pass should be routing/copper cleanup, not more placement:
  1. inspect U4 and U5 footprint copper directly
  2. route these first through the opened corridor:
    • I2C_SCL
    • I2C_SDA
    • NRST
    • crystal nets around Y2/C9/C10
    • PN7160 control nets
  3. then re-run PCB checks
If you want, I can next give you a U4/U5 hotspot routing checklist with the exact nets to route first and what to inspect on each footprint.
Give routing checklist
Check footprint copper
Run DRC review
List critical nets
a day

Placed components

5:16

Placed 14 component(s): R2, R5, U5, C9, C8, R3, J3, J2, C10, J1, R4, Y2, U4, C6

a day
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U4
U4 TX1 - U4 RXP
U4 IRQ - U5 PA1
D1 A - D2 K
U5 PB6 - U4 2C_SCL/SPI_SCK
U4 VDD(VMID) - C8 P1
U5 VDDA - C6 P1
U4 TX2 - U4 RXN
U4 VDD(TX) - U4 TVDD_IN
D3 A - D4 K
U5 PB7 - U4 I 2C_SDA/SPI_MISO
U4 DCDC_EN - U5 PA7
U4 CLK_REQ - U5 PA6
U6 EN - U4 VBAT
U4 VDD(TX) - U4 TVDD_IN
GND
J1 MP2 - R5 P2
U4 VSS(TX) - U4 EPAD
  • Ground
    Ground
    A common return path for electric current. Commonly known as ground.
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  • Net Portal
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    Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portal
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    Wirelessly connects power nets on schematic. Identical to the net portal, but with a power symbol. Used to organize schematics and separate functional blocks. To wirelessly connect power net portals, give them the same designator. #portal #power
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  • Generic Resistor
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    A generic fixed resistor ideal for rapid circuit topology development. Its footprint automatically adapts based on the selected package case code—supporting 0402, 0603, 0805, 1203, and many other standard SMD packages, as well as axial horizontal and vertical configurations. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard resistor values: 1.0 ohm, 10 ohm, 100 ohm, 1.0k ohm, 10k ohm, 100k ohm, 1.0M ohm 1.1 ohm, 11 ohm, 110 ohm, 1.1k ohm, 11k ohm, 110k ohm, 1.1M ohm 1.2 ohm, 12 ohm, 120 ohm, 1.2k ohm, 12k ohm, 120k ohm, 1.2M ohm 1.3 ohm, 13 ohm, 130 ohm, 1.3k ohm, 13k ohm, 130k ohm, 1.3M ohm 1.5 ohm, 15 ohm, 150 ohm, 1.5k ohm, 15k ohm, 150k ohm, 1.5M ohm 1.6 ohm, 16 ohm, 160 ohm, 1.6k ohm, 16k ohm, 160k ohm, 1.6M ohm 1.8 ohm, 18 ohm, 180 ohm, 1.8K ohm, 18k ohm, 180k ohm, 1.8M ohm 2.0 ohm, 20 ohm, 200 ohm, 2.0k ohm, 20k ohm, 200k ohm, 2.0M ohm 2.2 ohm, 22 ohm, 220 ohm, 2.2k ohm, 22k ohm, 220k ohm, 2.2M ohm 2.4 ohm, 24 ohm, 240 ohm, 2.4k ohm, 24k ohm, 240k ohm, 2.4M ohm 2.7 ohm, 27 ohm, 270 ohm, 2.7k ohm, 27k ohm, 270k ohm, 2.7M ohm 3.0 ohm, 30 ohm, 300 ohm, 3.0K ohm, 30K ohm, 300K ohm, 3.0M ohm 3.3 ohm, 33 ohm, 330 ohm, 3.3k ohm, 33k ohm, 330k ohm, 3.3M ohm 3.6 ohm, 36 ohm, 360 ohm, 3.6k ohm, 36k ohm, 360k ohm, 3.6M ohm 3.9 ohm, 39 ohm, 390 ohm, 3.9k ohm, 39k ohm, 390k ohm, 3.9M ohm 4.3 ohm, 43 ohm, 430 ohm, 4.3k ohm, 43K ohm, 430K ohm, 4.3M ohm 4.7 ohm, 47 ohm, 470 ohm, 4.7k ohm, 47k ohm, 470k ohm, 4.7M ohm 5.1 ohm, 51 ohm, 510 ohm, 5.1k ohm, 51k ohm, 510k ohm, 5.1M ohm 5.6 ohm, 56 ohm, 560 ohm, 5.6k ohm, 56k ohm, 560k ohm, 5.6M ohm 6.2 ohm, 62 ohm, 620 ohm, 6.2k ohm, 62K ohm, 620K ohm, 6.2M ohm 6.8 ohm, 68 ohm, 680 ohm, 6.8k ohm, 68k ohm, 680k ohm, 6.8M ohm 7.5 ohm, 75 ohm, 750 ohm, 7.5k ohm, 75k ohm, 750k ohm, 7.5M ohm 8.2 ohm, 82 ohm, 820 ohm, 8.2k ohm, 82k ohm, 820k ohm, 8.2M ohm 9.1 ohm, 91 ohm, 910 ohm, 9.1k ohm, 91k ohm, 910k ohm, 9.1M ohm #generics #CommonPartsLibrary
    jharwinbarrozo
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  • Generic Capacitor
    Generic Capacitor
    A generic fixed capacitor ideal for rapid circuit topology development. You can choose between polarized and non-polarized types, its symbol and the footprint will automatically adapt based on your selection. Supported options include standard SMD sizes for ceramic capacitors (e.g., 0402, 0603, 0805), SMD sizes for aluminum electrolytic capacitors, and through-hole footprints for polarized capacitors. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard capacitor values: 1.0pF, 10pF, 100pF, 1000pF, 0.01uF, 0.1uF, 1.0uF, 10uF, 100uF, 1000uF, 10000uF 1.1pF, 11pF, 110pF, 1100pF 1.2pF, 12pF, 120pF, 1200pF 1.3pF, 13pF, 130pF, 1300pF 1.5pF, 15pF, 150pF, 1500pF, 0.015uF, 0.15uF, 1.5uF, 15uF, 150uF, 1500uF 1.6pF, 16pF, 160pF, 1600pF 1.8pF, 18pF, 180pF, 1800pF 2.0pF, 20pF, 200pF, 2000pF 2.2pF, 22pF, 220pF, 2200pF, 0.022uF, 0.22uF, 2.2uF, 22uF, 220uF, 2200uF 2.4pF, 24pF, 240pF, 2400pF 2.7pF, 27pF, 270pF, 2700pF 3.0pF, 30pF, 300pF, 3000pF 3.3pF, 33pF, 330pF, 3300pF, 0.033uF, 0.33uF, 3.3uF, 33uF, 330uF, 3300uF 3.6pF, 36pF, 360pF, 3600pF 3.9pF, 39pF, 390pF, 3900pF 4.3pF, 43pF, 430pF, 4300pF 4.7pF, 47pF, 470pF, 4700pF, 0.047uF, 0.47uF, 4.7uF, 47uF, 470uF, 4700uF 5.1pF, 51pF, 510pF, 5100pF 5.6pF, 56pF, 560pF, 5600pF 6.2pF, 62pF, 620pF, 6200pF 6.8pF, 68pF, 680pF, 6800pF, 0.068uF, 0.68uF, 6.8uF, 68uF, 680uF, 6800uF 7.5pF, 75pF, 750pF, 7500pF 8.2pF, 82pF, 820pF, 8200pF 9.1pF, 91pF, 910pF, 9100pF #generics #CommonPartsLibrary
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  • Generic Inductor
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    A generic fixed inductor suitable for rapid circuit topology development. The footprint automatically adapts based on the selected package, supporting standard SMD sizes (e.g., 0402, 0603, 0805) as well as well-known inductor packages such as SDR1806, PA4320, SRN6028, and SRR1260. Standard inductor values: 1.0 nH, 10 nH, 100 nH, 1.0 µH, 10 µH, 100 µH, 1.0 mH 1.2 nH, 12 nH, 120 nH, 1.2 µH, 12 µH, 120 µH, 1.2 mH 1.5 nH, 15 nH, 150 nH, 1.5 µH, 15 µH, 150 µH, 1.5 mH 1.8 nH, 18 nH, 180 nH, 1.8 µH, 18 µH, 180 µH, 1.8 mH 2.2 nH, 22 nH, 220 nH, 2.2 µH, 22 µH, 220 µH, 2.2 mH 2.7 nH, 27 nH, 270 nH, 2.7 µH, 27 µH, 270 µH, 2.7 mH 3.3 nH, 33 nH, 330 nH, 3.3 µH, 33 µH, 330 µH, 3.3 mH 3.9 nH, 39 nH, 390 nH, 3.9 µH, 39 µH, 390 µH, 3.9 mH 4.7 nH, 47 nH, 470 nH, 4.7 µH, 47 µH, 470 µH, 4.7 mH 5.6 nH, 56 nH, 560 nH, 5.6 µH, 56 µH, 560 µH, 5.6 mH 6.8 nH, 68 nH, 680 nH, 6.8 µH, 68 µH, 680 µH, 6.8 mH 8.2 nH, 82 nH, 820 nH, 8.2 µH, 82 µH, 820 µH, 8.2 mH #generics #CommonPartsLibrary
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  • Terminal
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    An electrical connector acting as reusable interface to a conductor and creating a point where external circuits can be connected.
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    RMCF0805JT47K0
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Omni-Touch NFC Biometric Smart Card thumbnail
NFC-harvested Omni-Touch wearable board with PN7160 frontend, STM32L041 host MCU, SE050 secure element, palm-grid matrix interface, fingerprint UART connector, and status LED on a flex smart-card form factor.

Properties

Pricing & Availability

Distributor

Qty 1

Arrow

$9.76–$11.04

Digi-Key

$15.28–$16.29

LCSC

$21.40

Mouser

$18.02

TME

$0.00

Verical

$7.94–$13.20

Controls