Altium Designer

Altium Designer is a professional, subscription-licensed EDA tool with a large installed base at established PCB design houses, distinguished by its rule-driven design system, ECO-based schematic-to-PCB workflow, and integrated documentation tooling. This subtopic covers Altium at the practical workflow level: schematic entry through layout, generating fabrication and assembly drawings with Draftsman, and designing rigid-flex boards, alongside how Altium compares to KiCad for teams choosing between them.

What Is Altium Designer?

Altium Designer organises a design around a project file that links a schematic document, a PCB document, and library references, with components sourced from library parts that bundle a schematic symbol, PCB footprint, and supplier data in a single managed unit. Schematic changes transfer to the PCB through an Engineering Change Order (ECO), an explicit, reviewable diff rather than a silent netlist import. For the complete practical workflow, see How to Use Altium Designer: Schematic Entry and PCB Layout Workflow

This subtopic is part of the PCB Design topic.

Why Altium Matters

• The library/vault model is a team-scale decision, not just a personal preference. A database or Altium 365 vault keeps footprint and symbol data consistent across many concurrent projects; retrofitting centralised library management onto a project that started with ad hoc local libraries is significantly more work than establishing it up front.
• The ECO review step is a real checkpoint, not a formality. Rubber-stamping the Engineering Change Order dialog instead of reading it can let an unintended schematic change propagate silently to the board.
• Altium's binary project files don't fit a Git-native workflow. Teams that try to run an Altium project through the same branch-and-merge process as a text-based tool hit unresolvable merge conflicts; Altium 365's version history and release management is the supported alternative.
• Rigid-flex mechanical geometry has to be finalised before routing, not after. Retrofitting bend lines and Layer Stack Regions once traces already cross the flex zone usually forces a costly re-route.

Key Concepts

• Project file (.PrjPcb) — the container linking a schematic document, PCB document, and library references into one Altium project.
• Engineering Change Order (ECO) — the reviewable diff Altium generates when transferring schematic changes to the PCB via Design → Update PCB Document.
• Altium 365 vault — a cloud-hosted, version-controlled component library with lifecycle states, and Altium's answer to team-scale collaboration and release management in place of Git-native diffing.
• Layer Stack Region — the rigid-flex mechanism defining which layers are physically present in a given zone of the board, letting rigid and flex sections coexist in one PCB document. See rigid-flex design in Altium
• Draftsman — Altium's built-in documentation tool for generating live-linked fabrication and assembly drawings directly from the design data. See fabrication and assembly drawings in Draftsman

Common Mistakes

• Forgetting to compile the project before generating an ECO. An edited sheet that isn't part of the project's current compiled state produces a "no differences found" result even though the edit clearly exists — see the ECO troubleshooting thread for the full diagnostic.
• Applying one board-wide design rule set to a board with genuinely different regions (a high-voltage isolation section alongside dense digital routing) instead of using query-based rule scoping.
• Placing a component or via inside a rigid-flex bend area, which is either a reliability risk (unsupported flex substrate under a component) or a known fatigue-cracking site (a via in a repeatedly-flexed zone).
• Shipping a Draftsman drawing that's out of sync with the latest PCB revision because the document wasn't refreshed after a late layout change before export.

Common Questions

Should I use Altium Designer or KiCad for a new project?

It depends on team size, budget, and collaboration model more than raw layout capability. Both tools can produce a correct, manufacturable board. Altium tends to win for larger teams with vendor-support expectations, database-driven library governance, or heavy signal-integrity work; KiCad tends to win for budget-conscious and Git-centric teams. See Altium Designer vs KiCad for the full comparison.

Why does my Altium ECO say "no differences found" after I edited the schematic?

This almost always means the ECO is comparing against a stale compiled project state rather than your actual edit, commonly because the edited sheet was opened outside the project context (as a free document) or the project hasn't been recompiled since the edit. Right-click the project in the Projects panel and Compile Document, then regenerate the ECO. See the full troubleshooting thread for the related "Footprint Not Found" failure mode that often follows.

Do I still need to generate Gerbers if I'm using Draftsman?

Yes. Draftsman and Gerber/ODB++/IPC-2581 data serve different audiences, and neither replaces the other. Gerber-class data is machine-readable manufacturing data a fabricator's CAM software imports directly; Draftsman produces the human-readable dimensioned drawings an engineering team reviews alongside it. See fabrication and assembly drawings in Altium Draftsman for the full distinction.

Does a rigid-flex board need a different schematic workflow in Altium?

No. Schematic capture, library components, and the ECO-based transfer to the PCB are unchanged. Rigid-flex is a PCB-document-level mechanical concept: it's the layer stackup and Layer Stack Region definitions on the PCB side that differ, not how components and nets are captured on the schematic side. See rigid-flex design in Altium for the full workflow. Zeus Design designs PCBs in Altium Designer, including rigid-flex and high-speed layouts, from schematic entry through to production release.

Knowledge Base

Tool Comparison

• Altium Designer vs KiCad: Which PCB Design Tool Should You Use? — licensing cost, file formats, library management, team collaboration, and signal integrity tools compared

Workflow

• How to Use Altium Designer: Schematic Entry and PCB Layout Workflow — project structure, library-centric component model, ECO-based schematic-to-PCB transfer, design rules, and fabrication output

Documentation Output

• How Do You Generate Fabrication and Assembly Drawings in Altium Draftsman? — live-linked board/assembly views, drill and BOM tables, and ASME Y14.5 dimensioning practice

Rigid-Flex Design

• How Do You Design a Rigid-Flex PCB in Altium Designer? — Layer Stack Regions, bend lines vs bend areas, component/via placement restrictions, and coverlay/stiffeners

System-Level Design

• How Do You Design a Multi-Board System in Altium Designer? — multi-board schematic modules and connections, physical assembly and mates, cross-board connectivity checking, and system-level BOM

Forum Discussions

• Altium ECO says "no differences found" after I added components to the schematic — the stale-project-compilation cause, the related "Footprint Not Found" failure mode, and when local libraries stop scaling