Research
Leadless Flip Chip PLGA for Networking Applications
Influence of Manufacturing Quality on Thermomechanical Stress of Microvias
Designing a High Performance Electroless Nickel and Immersion Gold
Innovative of CU Electroplating Process for Any Layer Via Fillwith Planer Via Top and Thin Surface Copper
Acoustic Micro Imaging Analysis for 3D Packages
Conformal Coatings in Preventing Resistor Silver Sulfide Corrosion
Rework Challenges for Leading Edge Components BGA, QFN and LED
Compatibility and Aging for Flux and Cleaner Combinations
MORE RESEARCH
Latest Industry News
Globalization strikes back
Self-driving technology reaches a crossroads
The Art of Wanting Less
Amazon is everywhere. Here's how the US could break it up
The Best Laptops 2021
Foxconn installs advanced packaging equipment at China plant
Foxconn installs advanced packaging equipment at China plant
Here’s the latest proof that Apple is fixing the iPhone notch
MORE INDUSTRY NEWS

Atmospheric Plasma Surface Engineering of Printed Circuit Boards



Atmospheric Plasma Surface Engineering of Printed Circuit Boards
Plasma treatment is a method to increase the adhesion strength of the conformal coatings to PCBs through the removal of organic contaminants and surface activation.
Materials Tech

DOWNLOAD

Authored By:


Raul Gonzalez, Michael McCutchen, Richard Burke, Nathaniel Eternal,
Ed Laughlin, and Daphne Pappas
Plasmatreat USA, 30695 Huntwood Avenue, Hayward, CA 94544, USA

Summary


Conformal coatings are essential components for the microelectronics packaging industry. These functional coatings aim to protect electronic circuits from environmental factors such as heat and moisture. Typical coating formulations involve the use of epoxy, urethane and acrylic chemistries on polymer printed circuit boards (PCBs) leading to poor adhesion and failure to form void-free uniform coatings that follow the PCB skyline contour.

Plasma treatment is a novel method to increase the adhesion strength of the conformal protective coatings to PCBs through the removal of residual organic contaminants and surface activation. Poor adhesion can be a result of: i) incompatible materials, such as bonding polymers, ii) process residue: contaminants from fluxing, soldering and chemical treatments and iii) handling and storage conditions: fingerprints and dust. Plasma treatment under atmospheric pressure plasma (APP) conditions has emerged as an alternative solution for completely assembled PCBs which does not require a vacuum-based system. APP processes are fast and can be used for the treatment of selective areas of the board. The technology utilizes a dry gaseous medium and does not involve any harsh liquid solvent chemistries. Air-based APPs contain gaseous species that can react and remove organic surface contaminants very rapidly. Furthermore, they can be instrumental in the chemical functionalization and activation of the surface. In this paper, case studies from the application of air-based APPs for the cleaning of PCBs and the improved adhesion of conformal coatings will be presented.

Conclusions


Conformal coating on PCBAs has been a standard application for decades. However, manufacturers of electronic equipment face challenges like bubbles, orange peel, de-wetting, and delamination which are related to the cleanliness of the PCBA surface prior to the coating process. Atmospheric pressure plasmas can be effective in removing the surface contaminants. In Case Study 1, cleaning the PCBA surface with air-based plasma improved the average pull force, in pounds by 20%. Additionally, Case Study 2 showed, that plasma improved coverage resolution in three out of the four conformal coatings that were tested.

Comments

No comments have been submitted to date.

Submit A Comment


Comments are reviewed prior to posting. You must include your full name to have your comments posted. We will not post your email address.

Your Name


Your Company
Your E-mail


Your Country
Your Comments



Board Talk
What Causes Solder Icicles During Wave Soldering
Modify Rework Procedures for Assemblies Fabricated Using OSP?
Can High Particle Concentrations Impact PCB Assembly?
Review of Tin-Copper and Tin-Nickel Intermetallic Thickness
Moisture Barrier Bag Issues
Trouble With Skewed DPAK Components
Can Mixing Wave Solder Pallets Cause Contamination?
How to Reduce Voiding on QFN Components
MORE BOARD TALK
Ask the Experts
Suggested Limit for PCBA Heat Cycles
Average Temperature/Humidity for an Electronics Assembly Facility?
ENIG Solderability Issues
Very Low Temp PCBs
0201 Pick & Place Nozzle Plugging
IPC-A-610 Class 3 - IPC-A-600 Class 2
BGA Solder Ball Collapse
Baking After Cleaning Hand Placed Parts
MORE ASK THE EXPERTS