---
page_id: curated-cob-pad-frame
type: context-page
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template_id: curated-knowledge
template_version: template-0.1.0
title: CoB Pad Frame and Precheck
slug: curated-cob-pad-frame
route: /packaging-and-cob/pad-frame-and-precheck
section: reference
access: public
summary: CoB pad geometry, mapping, board compatibility, and golden-mask precheck.
status: published
asset_base: .
home_href: /
md_url: /packaging-and-cob/pad-frame-and-precheck.md
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tags: [wafer-space, knowledge-base, curated]
last_updated: 2026-08-19
talk_url: /packaging-and-cob/pad-frame-and-precheck.talk.md
talk_route: /packaging-and-cob/pad-frame-and-precheck/talk
---

# CoB Pad Frame and Precheck

This page owns CoB bond-pad geometry, pad mapping, slot-board compatibility, and the CoB-specific precheck.

## Reference pad frame

The 1x1 reference described on 2025-10-09 has 74 pads: 54 signal pads and 20 power or ground pads. Signal-pad types may change. Pad positions and the power/ground arrangement should not change. **Confirmed guidance by Leo Moser.** ([archive message](/evidence/designing/cob#message-1425749959227080724); [Discord](https://discord.com/channels/1361349522684510449/1408134567491145728/1425749959227080724))

The template workflow maps pads in `config.yaml` and instantiates them in `chip_top.sv`. Leo Moser warned that a different pad ring needs another wire-bonding setup. **Confirmed guidance, 2025-10-27.** ([archive message](/evidence/designing/cob/threads/gf180mcu-project-template#message-1432270303668604948); [Discord](https://discord.com/channels/1361349522684510449/1431949282944221267/1432270303668604948))

## Precheck history

- **2026-06-03 — Confirmed release.** Template 1.5.0 and precheck 1.6.0 added configurable SCL, PAD, and SRAM choices, the `--cob` check, and the parallel DRC runner. ([archive message](/evidence/designing/project-template#message-1511722026648338514); [Discord](https://discord.com/channels/1361349522684510449/1423348662318272592/1511722026648338514))
- **2026-06-18 — Corrective action.** Template 1.5.3 fixed a 0.5 µm north/south pad-position regression. Precheck 1.7.0 added a golden pad-mask check for CoB. Version 1.5.0 geometry is obsolete guidance where it conflicts with 1.5.3. ([archive message](/evidence/designing/project-template#message-1517130928248586290); [Discord](https://discord.com/channels/1361349522684510449/1423348662318272592/1517130928248586290))
- **2026-07-10 — Run 2 guidance.** The CoB setting changes precheck flags and verifies the expected pad layout. The deadline in the announcement is historical; the described check is durable. ([archive message](/evidence/admin/announcements#message-1524956674861957282); [Discord](https://discord.com/channels/1361349522684510449/1361349523724570938/1524956674861957282))
- **2026-08-13 — Latest captured boundary.** Manufacturing may accept any DRC-clean design, but CoB requires pads at the coordinates expected by the bonder. This is captured search evidence; its canonical Discord URL was not captured. ([archive message](/evidence/live-delta/designing/analog#message-1537441624102141982))

## Slot-board compatibility

The 1x0p5 board was reported power/ground compatible with 1x1. Pads 67 through 70 are reversed, so it is not fully signal-pin compatible. **Confirmed design report, 2026-06-15.** ([archive message](/evidence/designing/project-template#message-1516120547476373668); [Discord](https://discord.com/channels/1361349522684510449/1423348662318272592/1516120547476373668))

**Proposal, 2026-05-24:** Harmonizing all slot pinouts and avoiding half-slot die rotation were proposed, but the cited message does not show adoption. ([archive message](/evidence/designing/cob/threads/cob-pcb-and-die-sizes#message-1508113764741025824); [Discord](https://discord.com/channels/1361349522684510449/1507457326225821758/1508113764741025824))

## Conflict

BreakingTaps later said signal types can change and thought power pads might change, but marked that point uncertain. The earlier specific guidance says power/ground pads should not change. Use the fixed rule until the current golden mask supplies contrary evidence. ([archive message](/evidence/designing/analog#message-1534312011234807838); [Discord](https://discord.com/channels/1361349522684510449/1408135265427394661/1534312011234807838)) ([archive message](/evidence/designing/cob#message-1425749959227080724); [Discord](https://discord.com/channels/1361349522684510449/1408134567491145728/1425749959227080724))

## Related pages

- [Packaging and Chip on Board](/packaging-and-cob)
- [CoB Production History](/packaging-and-cob/production-history)
- [Analog I/O and ESD](/analog-design/io-and-esd)
- [Precheck and Signoff](/submission-procedures/precheck-and-signoff)

## Sources

- `1425749959227080724` — 2025-10-09T07:41:19.433Z — Leo Moser (mole99) — [archive message](/evidence/designing/cob#message-1425749959227080724); [Discord](https://discord.com/channels/1361349522684510449/1408134567491145728/1425749959227080724) — 74-pad reference and fixed geometry.
- `1432270303668604948` — 2025-10-27T07:30:50.690Z — Leo Moser (mole99) — [archive message](/evidence/designing/cob/threads/gf180mcu-project-template#message-1432270303668604948); [Discord](https://discord.com/channels/1361349522684510449/1431949282944221267/1432270303668604948) — Pad mapping and bonding setup.
- `1511722026648338514` — 2026-06-03T13:23:37.590Z — Leo Moser (mole99) — [archive message](/evidence/designing/project-template#message-1511722026648338514); [Discord](https://discord.com/channels/1361349522684510449/1423348662318272592/1511722026648338514) — Template 1.5.0 and precheck 1.6.0.
- `1508113764741025824` — 2026-05-24T14:25:40.913Z — RebelMike — [archive message](/evidence/designing/cob/threads/cob-pcb-and-die-sizes#message-1508113764741025824); [Discord](https://discord.com/channels/1361349522684510449/1507457326225821758/1508113764741025824) — Pinout-harmonization proposal.
- `1516120547476373668` — 2026-06-15T16:41:46.676Z — RebelMike — [archive message](/evidence/designing/project-template#message-1516120547476373668); [Discord](https://discord.com/channels/1361349522684510449/1423348662318272592/1516120547476373668) — Slot-board compatibility.
- `1517130928248586290` — 2026-06-18T11:36:40.224Z — Leo Moser (mole99) — [archive message](/evidence/designing/project-template#message-1517130928248586290); [Discord](https://discord.com/channels/1361349522684510449/1423348662318272592/1517130928248586290) — Pad regression fix and golden mask.
- `1524956674861957282` — 2026-07-10T01:53:23.612Z — Tim 'mithro' Ansell — [archive message](/evidence/admin/announcements#message-1524956674861957282); [Discord](https://discord.com/channels/1361349522684510449/1361349523724570938/1524956674861957282) — CoB precheck setting.
- `1534312011234807838` — 2026-08-04T21:28:09.617Z — BreakingTaps — [archive message](/evidence/designing/analog#message-1534312011234807838); [Discord](https://discord.com/channels/1361349522684510449/1408135265427394661/1534312011234807838) — Uncertain power-pad opinion.
- `1537441624102141982` — 2026-08-13T12:44:07.470Z — Leo Moser (mole99) — [archive message](/evidence/live-delta/designing/analog#message-1537441624102141982) — CoB coordinate boundary; canonical Discord URL not captured.