> ## Documentation Index
> Fetch the complete documentation index at: https://docs.buildwithtrace.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Design Review

> AI-powered pre-flight manufacturing check that validates your board against DRC, signal integrity, and DFM constraints before ordering.

## What It Does

Design Review is an AI-powered pre-flight check that validates your entire design before you send it to manufacturing. It runs DRC, traces signal paths for integrity issues, checks DFM compliance against your target manufacturer, and reports everything in a single pass.

Think of it as a senior engineer reviewing your board before it goes to fab — except it runs in seconds and never misses a constraint.

## When It Runs

Design Review can be triggered in three ways:

1. **From the "Send to Manufacturer" dialog** — Trace automatically runs a review before submitting your order. If critical issues are found, you're prompted to fix them before proceeding.
2. **From the chat** — Ask the AI: "Review my design", "Run a pre-flight check", or "Is this board ready for manufacturing?"
3. **From the CLI** — `buildwithtrace review ./my-board/` runs a comprehensive review and outputs a report.

## What It Checks

### Electrical Rule Check (ERC)

* Unconnected pins that should be connected
* Power pin conflicts (multiple drivers on a net)
* Missing power flags on power nets
* Undriven input pins

### Design Rule Check (DRC)

* Trace width and spacing violations
* Via drill size and annular ring minimums
* Courtyard overlap between components
* Board edge clearance violations
* Unrouted nets (incomplete routing)
* Copper-to-edge clearance
* Silkscreen over pads

### Signal Integrity

* High-speed trace length matching (USB, DDR, PCIe)
* Differential pair spacing consistency
* Reference plane continuity under critical signals
* Via stub length on high-speed nets
* Impedance discontinuities at layer transitions

### Design for Manufacturing (DFM)

* Minimum feature sizes below your fab's capability
* Drill aspect ratio limits
* Acid trap detection (acute angles in copper)
* Solder bridge risk (tight pin spacing without mask dams)
* Thermal relief adequacy on large copper pours
* Silkscreen legibility (text too small for your fab)
* Panelization compatibility

### Component & BOM

* End-of-life or NRND (Not Recommended for New Design) parts
* Single-source components with no alternates
* Footprint-to-datasheet mismatch detection
* Missing MPN (Manufacturer Part Number) entries

## Using Design Review

### From the Desktop App

Ask the AI in the chat panel:

```
Review my design before manufacturing
```

Or trigger it from the manufacturing flow:

<Steps>
  <Step title="Open the manufacturing dialog">
    Go to **File → Send to Manufacturer** or ask the AI "Order this board from PCBWay."
  </Step>

  <Step title="Review runs automatically">
    Before the order form appears, Trace runs a design review against your selected manufacturer's capabilities.
  </Step>

  <Step title="Review the results">
    The AI presents findings grouped by severity: **Critical** (must fix), **Warning** (should fix), and **Info** (awareness only).
  </Step>

  <Step title="Fix or proceed">
    Ask the AI to fix issues ("Fix all DRC violations") or proceed with acknowledged warnings.
  </Step>
</Steps>

### From the CLI

```bash theme={null}
buildwithtrace review ./my-board/ --output review.md
```

Options:

| Flag              | Description                                                                      |
| ----------------- | -------------------------------------------------------------------------------- |
| `--scope <type>`  | `full` (default), `schematic`, `pcb`, `bom`                                      |
| `--focus <areas>` | Comma-separated: `routing`, `thermal`, `impedance`, `dfm`, `components`, `power` |
| `--format <type>` | `text` (default), `json`, `markdown`                                             |
| `--output <file>` | Write the report to a file                                                       |

```bash theme={null}
buildwithtrace review ./my-board/ --focus dfm,impedance
buildwithtrace review ./my-board/ --scope pcb --format json
```

## Severity Levels

| Level        | Meaning                                                  | Action Required             |
| ------------ | -------------------------------------------------------- | --------------------------- |
| **Critical** | Will cause manufacturing failure or non-functional board | Must fix before ordering    |
| **Warning**  | May cause issues or reduce yield                         | Strongly recommended to fix |
| **Info**     | Best practice suggestion or minor cosmetic issue         | Fix if convenient           |

## Example Output

```
═══ Design Review: Smart Sensor Hub ═══

CRITICAL (2 issues)
  ├─ DRC: Trace clearance 3.2mil on net USB_DP (min: 5mil for JLCPCB 4-layer)
  └─ DRC: Via drill 0.15mm below manufacturer minimum (0.2mm)

WARNING (3 issues)
  ├─ Signal: USB_DN/USB_DP length mismatch 4.2mm (target: <2.5mm)
  ├─ DFM: Silkscreen text "R14" overlaps solder mask opening
  └─ BOM: U3 (TPS62840) single-source, no approved alternates

INFO (1 issue)
  └─ Layout: Decoupling cap C7 is 3.1mm from U1 pin 12 (rule: <2mm)

Recommendation: Fix 2 critical issues before ordering.
```

## Integration with TraceRules

If your `.trace/rules.md` specifies a manufacturer target, Design Review automatically validates against that manufacturer's capabilities:

```markdown theme={null}
## Manufacturer
- Fab: JLCPCB 4-layer, 1.0mm thickness
- Min trace/space: 0.127mm/0.127mm
- Min via: 0.2mm drill
```

The AI uses these constraints as the validation baseline, catching issues that a generic DRC would miss.

## Continuous Design Review

Design Review isn't just a one-shot pre-manufacturing step. During active design sessions in Agent or Plan mode, the AI continuously monitors for violations as it makes changes — fixing them in real-time rather than accumulating them for a final review pass.

<Tip>
  Run Design Review early and often, not just before ordering. A quick `buildwithtrace review ./my-board/ --focus routing` after finishing a routing session catches issues while the context is fresh.
</Tip>

## Related

* [One-Click Manufacturing](/guides/one-click-manufacturing) — Order PCBs directly from Trace
* [DRC Rule Editor](/concepts/drc-rule-editor) — Configure design rules visually
* [DRC Import](/concepts/drc-import) — Load manufacturer constraint files
* [DFM & the Automated Line](/concepts/dfm-and-the-automated-line) — How Trace fits into the manufacturing pipeline