Confirmed — I’ll rebuild the layout with GPT’s per-well assignment exactly and use three separate SMB footprints with isolated shells. I’ll remove the row-bar placeholder and 1×3 header, add the per-well cells, then verify the geometry.
I replaced the placeholder electrode field with per-well WE/RE/CE islands and added three separate SMB-style footprints with isolated shell nets. I’m verifying the read-back and updating the project notes now.
Worked for 7 mins 59 sec
47 days ago
Thought for 3 mins 16 sec — Updating todos
4/5 Verify layout geometry and DRC-relevant issues
Remove/disable current row-bar placeholder electrodes and 1x3 header
Add GPT per-well WE/RE/CE electrode geometry on 9 mm pitch
Add three SMB connector footprints with isolated shell pads
Verify layout geometry and DRC-relevant issues
Update project specification with the corrected per-well design
DXF print masks for Ag/AgCl reference and carbon counter electrodes
CSV coordinate table
Key geometry from the GPT proposal
Board
Outer dimensions: 127.76 mm x 85.48 mm
Thickness: 2.0 mm
4 copper layers: F.Cu, In1.Cu, In2.Cu, B.Cu
5 mm x 5 mm chamfer at one corner
8 x 12 well array
9.00 mm pitch
A1 center: 14.38 mm from left edge, 11.24 mm from top edge
Wetted opening diameter: 5.46 mm
Suggested gasket opening: about 5.60 mm ID
Suggested gasket OD: about 7.20 mm
Per-well electrode cell
Each well has three separate local electrodes rather than cross-well row bars:
Table
Electrode
Net
Shape
Position relative to well center
Approx. size
Working
WE_GLOBAL
circular disk
center
2.00 mm diameter
Reference
RE_GLOBAL
left crescent/landing
x about -1.82 mm
about 1.18 mm x 2.35 mm bounding box
Counter
CE_GLOBAL
right larger landing
x about +1.92 mm anchor
about 2.37 mm x 5.12 mm bounding box
Important: this differs from the earlier user idea of a central counter electrode. The GPT proposal uses the central disk as WE, left pad as RE, and right pad as CE.
Connectivity
All 96 WE pads are tied to WE_GLOBAL.
All 96 RE pads are tied to RE_GLOBAL.
All 96 CE pads are tied to CE_GLOBAL.
Therefore the plate remains one global parallel electrochemical cell, not 96 independently addressed wells.
Routing approach
F.Cu: exposed electrodes and local fanout
In1.Cu: WE row buses/trunk
B.Cu: RE row buses/trunk
In2.Cu: CE row buses/trunk
288 vias total, three per well
Suggested via size: 0.60 mm, drill 0.30 mm
Via offsets keep vias outside the suggested gasket OD
SMB connector update
The user requested three separate SMB connectors instead of one 3-pin header.
Flux library search did not find a direct SMB 50 ohm female PCB jack part with a usable library footprint. Web research found suitable real SMB PCB jack candidates:
Table
Candidate
Manufacturer
Notes
Molex 731000207
Molex
SMB Jack, vertical PCB, 50 ohm; official drawing provides a simple 5-hole through-hole pattern
Amphenol 903-415J-51P
Amphenol RF
SMB PCB through-hole straight jack, 50 ohm; official drawing available
TE/Linx CONSMB002-G
TE Connectivity / Linx
SMB jack 50 ohm PCB through-hole right angle; drawing/CAD available
Recommended default for this project: Molex 731000207 vertical through-hole SMB jack, because its drawing gives a clean 5-hole footprint.
Molex 731000207 footprint summary
Using center signal hole as origin:
Table
Hole
Function
X
Y
Drill
1
Signal center contact
0.00 mm
0.00 mm
1.20 mm
2
Shell/shield leg
-2.54 mm
+2.54 mm
1.20 mm
3
Shell/shield leg
+2.54 mm
+2.54 mm
1.20 mm
4
Shell/shield leg
-2.54 mm
-2.54 mm
1.20 mm
5
Shell/shield leg
+2.54 mm
-2.54 mm
1.20 mm
Open design decision: whether the three SMB connector shells should be:
Left isolated from electrode nets and from each other,
Tied together on a shield/chassis net, or
Tied to a controller-side reference/ground strategy later.
For the passive plate, the safest first-pass choice is isolated shell pads per connector unless the controller architecture requires a common shield.
Required changes to the current Flux layout
The current Flux layout should be revised as follows:
Remove or disable the existing long WE/RE row bars.
Remove or disable the existing central CE dots.
Replace the electrode field with 96 repeated local three-electrode cells based on the GPT geometry.
Remove the current 1 x 3 connector J1.
Add three separate SMB footprints near the right edge or top edge:
J_WE center pin to WE_GLOBAL
J_RE center pin to RE_GLOBAL
J_CE center pin to CE_GLOBAL
Keep row/column labels and Bio-Rad dimensions.
Add test pads only if they do not interfere with the SMB connectors and gasket area.
Re-run layout checks after geometry replacement.
Recommended next design confirmation
Before mutating the layout, confirm two design choices:
Electrode assignment: use GPT geometry exactly, meaning central disk = WE, left pad = RE, right pad = CE.
SMB shell behavior: isolate the shell pads, tie the four shell pads of each connector together only, or tie all connector shells to a common shield net.