Issue link: https://iconnect007.uberflip.com/i/1535414
10 PCB007 MAGAZINE I MAY 2025 Feature Article by Marcy LaRont I-CONNECT007 In printed circuit board (PCB) fabrication, surface preparation is a critical process that ensures strong adhesion, reliable plating, and long-term product performance. Without proper surface treatment, manufacturers may encounter defects such as delamination, poor solder mask adhesion, and plating failures. is article examines key surface preparation techniques, common defects resulting from improper processes, and real-world case stud- ies that illustrate best practices. Types of Surface Preparation Mechanical Surface Preparation Mechanical techniques physically remove oxidation, contaminants, and residues while roughening the surface for better adhesion. • Brushing (scrubbing): Rotating abrasive brushes clean the copper surface and enhance adhesion for dry film lamination and solder mask application. › Risks: Overbrushing can reduce copper thickness and damage fine traces, while under brushing leaves oxidation, leading to poor adhesion. You can also develop prob- lems via smear from the brushes if they are worn or if the pressure is too high. › Prevention: Use controlled brush pres- sure and monitor brush wear to maintain uniform abrasion. Implement process val- idation with cross-sectioning to ensure proper copper thickness retention. • Abrasive Blasting (microblasting): Fine aluminum oxide or glass beads roughen PTFE and other difficult-to-bond substrates. Preventing Surface Prep Defects and Ensuring Reliability