Dan’s Biz Bookshelf: ‘The Next RenAIssance: AI and the Expansion of Human Potential’
The Chemical Connection: When the Industry Moves Faster Than the Standards
Driving Innovation: Selecting the Right Laser Source
Henniker Plasma: Plasma Treatment of Fluoropolymers
February 14, 2023 | Henniker PlasmaEstimated reading time: 2 minutes
PTFE, and other fluorinated polymers, are chemically inert, thermally stable and highly hydrophobic, due to their intrinsically low surface energy. The chemical inertness of PTFE as an example, means that it is virtually impossible to form lasting adhesive bonds and coatings tend instead to form droplets and 3D particles on the surface rather than a uniform film. Traditional methods to increase the surface energy involve the use of aggressive primers which represent an ecological hazard.
Fluorinated polymers are not readily modified by standard plasma processes. Oxygen plasmas, which are successfully used to treat many hydrocarbon-based polymers, are not successful because the binding energy of the fluorine to carbon atom is far higher than that of oxygen to carbon. Plasma treatment of fluorinated polymers with oxygen plasmas instead causes a gradual etching of the surface, as opposed to surface activation.
The use of hydrogen plasma on the other hand, produces an immediate and lasting change in the nature of the fluoropolymer surface. The action of atomic hydrogen, generated by the plasma, is to react with surface fluorine and remove this into the gas phase where it is pumped away by the vacuum system. Hydrogen then terminates the free surface bonds to produce a CHx polymer surface which is readily wettable. The resulting surface is also mildly-etched on a microscopic scale which produces a microscopically structured surface. Both actions in combination result in a modified surface which may be glued, painted etc.
Typical Results
Results, below and across, show the change in morphology, water contact angle and surface energy obtained for PTFE following hydrogen plasma treatment. The surface energy of PTFE that has been plasma treated is actually lower than that of many common polyolefins, such as polyethylene and polypropylene, and well within the range of wettability required for many adhesives to form strong bonds.
Plasma Process
When gas atoms are ionised, the collision of high energy particles knocks electrons out of their orbits. This results in the characteristic “glow” or light associated with plasma. Plasmas many different species including atoms, molecules, ions, electrons, free radicals, metastables, and photons in the short wave ultraviolet (vacuum UV or VUV) range. Plasmas are generated in closed vessels at low pressures, typically < 1.0 Torr. The low pressure results in a long mean free path of the plasma species, so that they remain reactive until contact with a surface. The overall chamber temperature at the commonly used power levels and pressures is close to room temperature
Share on:
Testimonial
"Your magazines are a great platform for people to exchange knowledge. Thank you for the work that you do."
Simon Khesin - Schmoll MaschinenSuggested Items
Elsyca Acquires Hivelix to Strengthen Simulation Platform for Electrochemical Surface Engineering
04/03/2026 | ElsycaElsyca, a global pioneer in computer-aided engineering (CAE) simulation for electrochemical processes and surface finishing, announces the acquisition of Hivelix, a specialist in advanced surface treatment simulation with strong expertise in multiphysics modelling and AI-assisted process optimisation.
Connect the Dots: Designing for the Future of Manufacturing Reality—Solder Mask and Legend
04/09/2026 | Matt Stevenson -- Column: Connect the DotsPCBs seem to be getting more complex by the day, so it is important for designers to keep educating themselves about the realities of manufacturing increasingly intricate boards. Last month’s column highlighted design considerations for the strip-etch-strip process and how manufacturers approach that phase of production. Now that we have a functioning board, we must protect the PCB from environmental hazards and document the circuit components. This article will detail the solder mask and legend process and offer best practices for designers to ensure a high-quality result.
Take the Mic: Photo Chemical Systems: 50 Years Strong
04/03/2026 | Real Time with... APEX EXPOPhoto Chemical Systems is celebrating 50 years in the bare board PCB market. David Graves and Jason Averette discuss how they've expanded into assembly, leveraging strong relationships and a customer-centric approach to navigate supply chain challenges. With innovative solutions and future growth strategies, including AI integration and new market ventures, Photo Chemical Systems continues enduring success.
Bold Laser Automation Introduces Precision Laser Cleaning System for Advanced Manufacturing
03/27/2026 | PRNewswireBold Laser Automation, Inc. has introduced the LPCl1820UV Laser Precision Cleaning System, a Class 1, industrial laser platform engineered for high-precision surface cleaning and thin-film removal in demanding manufacturing environments.
The Chemical Connection: Managing Cumulative Process Variations for Fun and Profit
03/23/2026 | Don Ball -- Column: The Chemical ConnectionTolerances have become increasingly tight as PCBs have grown more complex and reduced in size, weight, and power consumption. Even if we maintain a traditional ±10% variation in etched line width, the tolerance in a 50 µm (0.002" or 2 mils) wide etched line is only 5 µm (0.0002” or 0.2 mils). That’s not very much, and it gets even worse as the line and space requirements drop to 25 µm lines and spaces.