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Complete Design

This lesson walks through a complete AP 210 design: a Surface Mount Flasher board. This example demonstrates how all the concepts from previous lessons come together in a real design.

The Surface Mount Flasher

The Surface Mount Flasher is a small printed circuit assembly that includes:

  • A PCB (single or double-sided)

  • Several surface mount components (resistors, capacitors, LEDs, IC)

  • Connectivity between components

  • A specific board outline shape

File Structure Overview

The STEP file follows the standard pattern:

  1. Header - File metadata, schema declaration

  2. Application context - Identifies this as AP 210 data

  3. Product definitions - The board and each component

  4. Assembly structure - How components are assembled on the board

  5. Shape data - Geometric representations of all parts

  6. Connectivity - Net list and trace routing

  7. Properties - Material, electrical, and thermal properties

Product Hierarchy

Surface Mount Flasher (product)
  ├── PCB (product_definition)
  ├── R1 - Resistor (product)
  │     └── R1 instance on board (assembly usage)
  ├── C1 - Capacitor (product)
  │     └── C1 instance on board (assembly usage)
  ├── U1 - LED (product)
  │     └── U1 instance on board (assembly usage)
  └── U2 - IC (product)
        └── U2 instance on board (assembly usage)

Key Entities to Trace

When reading this file:

  1. Start: APPLICATION_CONTEXT('electronic assembly…​')

  2. Top product: PRODUCT('Surface Mount Flasher', …​)

  3. Components: Multiple PRODUCT entities for each part

  4. Assembly: NEXT_ASSEMBLY_USAGE_OCCURRENCE linking components to board

  5. Placement: ITEM_DEFINED_TRANSFORMATION for each component position

  6. Nets: PHYSICAL_CONNECTIVITY_DEFINITION for each net

  7. Traces: PATH or POLYLINE geometry on each stratum

Reading Strategy

For a complete design, focus on one aspect at a time:

  • Structure - Who are the components and how are they organized?

  • Geometry - What are the shapes and where are they placed?

  • Connectivity - What is connected to what?

  • Properties - What are the material and electrical values?

Trying to read all aspects simultaneously is overwhelming. Each pass through the file builds understanding incrementally.