A bottom-side assembly drawing can be interpreted either as looking directly at the bottom of the board or as looking through the board from above. If the view is not clearly defined, an otherwise accurate drawing can cause an orientation mistake. State the viewing direction and verify it with asymmetric features.
Altium’s board-assembly view documentation describes generated views using board and component graphics with configurable captions and reference markers. Review the selected data sources and view settings; automatic generation does not remove the need to check their meaning.
Establish the viewing convention
Label each view with the board side and viewing direction. Use a connector, keyed notch, or unequal mounting-hole pattern to demonstrate orientation. Do not rely only on a rectangular outline or a symmetric component arrangement.
Keep assembly-view conventions distinct from machine placement coordinates. A visually mirrored bottom view may be appropriate for an operator looking at that side, while the placement system uses a different coordinate convention. Document each output according to its actual purpose.
Check the information an operator uses
| Drawing element | Review question |
|---|---|
| Component references | Are labels readable and tied to the correct body? |
| Pin-one or polarity cue | Does it match the component and footprint documentation? |
| Population state | Does the view represent the intended assembly variant? |
| Board features | Can the operator orient the physical assembly confidently? |
Inspect crowded areas at the final drawing scale. A label that is clear while zoomed in may overlap several components on the printed sheet. Use detail views or controlled callouts where necessary instead of relying on extremely small text. Check that leader lines terminate at the intended component and that a manually moved caption has not remained behind after a later placement update. Review the exported page without other EDA layers visible.
Reconcile with the other assembly files
- Compare fitted references with the BOM.
- Check board side and orientation against placement data.
- Review polarized components individually.
- Confirm that manual annotations still match the generated view.
- Open the final exported PDF for review.
Do not use a decorative body graphic as the sole polarity definition if it lacks a reliable pin-one indicator. Reference the exact component drawing or controlled assembly note when the package appearance is ambiguous.
Close the review with a drawing that can be understood independently of the EDA screen. Include revision and variant identity so a detached page remains useful. The placement-origin guide addresses the complementary machine-data question of how each component’s coordinates and rotation are defined.
Move from reading to a build-ready project
Use the fabrication and assembly checklists to prepare drawings, production files and test requirements.
Open the DFM checklist