Printed Circuit Board Fabrication Process Flow

1. Artwork Generation

• Create a digital design file (e.g., Gerber files) containing the circuit layout.

2. Film Generation (Photoplotting)

• Expose the design onto a photo-sensitive film (e.g., photoresist) using a photoplotter.

3. Pre-Laminate Preparation

• Clean and prepare the copper-clad laminate (base material) by applying an adhesive.
• Apply the photoresist film to the laminate.

4. Exposure

• Expose the photoresist film to ultraviolet (UV) light through the film mask.
• The exposed areas harden, while the unexposed areas remain soft.

5. Development

• Remove the unexposed photoresist using a chemical developer.

6. Etching

• Etch the exposed copper areas using a chemical etchant (e.g., ferric chloride).
• The etchant removes the unwanted copper, leaving behind the desired circuit pattern.

7. Stripping

• Remove the remaining photoresist using a chemical stripper.

8. Plating

• Apply a thin layer of copper over the exposed areas to increase conductivity (e.g., electrolytic copper plating).

9. Hole Drilling

• Drill holes for component leads and vias using a CNC drilling machine.

10. Solder Mask Application

• Apply a protective solder mask material to the board, leaving only the solder pads exposed.

11. Silkscreen Printing

• Print component references and other markings onto the board using a silkscreen printer.

12. Component Assembly

• Place components on the board and solder them in place using a solder paste printer and reflow oven.

13. Functional Testing

• Test the board for electrical functionality using automated test equipment (ATE).

14. Final Inspection

• Visually inspect the board for any defects or errors.