Step-by-Step Rigid PCB Fabrication Process

1. Design (PCB Layout)

• Done using software like Altium Designer or KiCad
• Engineers design:
  • Circuit connections (schematic)
  • Board layout (placement + routing)

2. Printing the Design (Photoplotting)

• The PCB design is printed onto a transparent film (photomask).
• This film acts as a stencil for circuit patterns.

3. Substrate Preparation

• Base material: FR-4 laminate
• Copper layers are bonded on one or both sides.

4.  Photoresist Application & Exposure

• A photoresist layer is applied to copper.
• UV light is used to transfer the circuit pattern from the mask.
• Exposed/unexposed areas change chemically.

5.  Etching

• Unwanted copper is removed using chemicals.
• Only the desired circuit traces remain.

6.  Drilling

• Holes are drilled for:
  • Components (through-hole)
  • Vias (connections between layers)

7.  Plating

• Holes are plated with copper (electroplating).
• Ensures electrical connections across layers.

8.  Solder Mask Application

• A protective layer (usually green) is applied.
• Prevents:
  • Short circuits
  • Oxidation

9.  Silkscreen Printing

• Labels like:
  • Component names
  • Logos
• Printed on the PCB.

10.  Testing & Inspection

• Electrical testing ensures no faults.
• Common tests:
  • Continuity test
  • Automated Optical Inspection (AOI)

 Types of Rigid PCBs

• Single-layer
• Double-layer
• Multi-layer (e.g., 4-layer, 6-layer, etc.)

 Key Materials Used

• FR-4 (Fiberglass epoxy)
• Copper foil
• Photoresist chemicals
• Solder mask ink

 Advantages

• Strong and durable
• Cost-effective for mass production
• Reliable electrical performance

Limitations

• Cannot bend or fold
• Takes more space compared to flexible PCBs