PCB Fabrication Training

The following are the core modules and topics standard in PCB fabrication training programs:

Introduction and Materials

• Basics of PCB Technology: History, classification (single-sided, double-sided, multi-layer), and single vs. multi-layer limitations.
• PCB Materials: Study of substrates (Standard FR-4, multifunctional FR-4, Teflon, Nelco N400-6) and resin systems.
• Substrate Preparation: Cutting copper-clad laminates and manual/mechanical cleaning methods.

Core Fabrication Processes

• Imaging and Patterns: Techniques including photo printing, screen printing, and Laser Direct Imaging (LDI) to create circuitry patterns on photoresist layers.
• Etching: Chemical principles and mechanisms for removing excess copper from inner and outer layers.
• Multi-layer Lamination: Stack-up design, lay-up process, and press cycles to bond board materials at high temperatures.

Via Formation and Plating

• Drilling Operations: Basics of mechanical and laser drilling for mounting holes and vias.
• Desmear and Etchback: Removing drill smear from hole walls to ensure reliable electrical contact.
• Metallization and Electroplating: Processes like electroless copper deposition and electroplating to plate drilled holes and thicken copper traces.

Surface Finishing and Legend Marking

• Solder Mask Application: Coatings applied for extra protection, patterned via UV light imaging.
• Surface Finishes: Selecting finishes like HASL, OSP, ENIG/ENEPIG, Immersion Silver, and Immersion Tin.
• Silkscreen/Legend Printing: Adding reference and polarity indicators, logos, and markings to the surface.

Post-Fabrication and Quality Control

• Electrical Testing: Verifying the bare board's electrical continuity and isolation.
• Inspection Methods: Techniques include Manual Visual Inspection, Automated Optical Inspection (AOI), and X-Ray Inspection.
• IPC Standards: Qualification and performance specifications, such as IPC-6011 (Generic) and IPC-6012 (Rigid Printed Boards).

Design for Manufacturing (DfM)

• Manufacturing Constraints: Understanding tolerances, pad-to-hole relationships, and minimum trace/spacing rules (e.g., the 3W rule).
• File Generation: Generating standard outputs for manufacturing, including Gerber files and N/C Drill data.
• Fabrication Documentation: Creation of fabrication drawings/prints containing default rigid PCB specs and board outlines