-
- News
- Books
Featured Books
- pcb007 Magazine
Latest Issues
Current IssueThe Growing Industry
In this issue of PCB007 Magazine, we talk with leading economic experts, advocacy specialists in Washington, D.C., and PCB company leadership to get a well-rounded picture of what’s happening in the industry today. Don’t miss it.
The Sustainability Issue
Sustainability is one of the most widely used terms in business today, especially for electronics and manufacturing but what does it mean to you? We explore the environmental, business, and economic impacts.
The Fabricator’s Guide to IPC APEX EXPO
This issue previews many of the important events taking place at this year's show and highlights some changes and opportunities. So, buckle up. We are counting down to IPC APEX EXPO 2024.
- Articles
- Columns
Search Console
- Links
- Events
||| MENU - pcb007 Magazine
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
Suggested Items
Real Time with… IPC APEX EXPO 2024: Exploring the Future of Surface Finishes
04/25/2024 | Real Time with...IPC APEX EXPOJoe McGurran, product marketing director for MKS Atotech, looks into the future of surface finishes, discussing less nickel, reduced thickness, technologies influencing HDI and UHDI, and the benefits of nickel-free surface finishes. He also touches on popular finishes like ENIG and palladium immersion gold and discusses the value proposition of making a change.
Designer’s Notebook: What Designers Need to Know About Manufacturing, Part 2
04/24/2024 | Vern Solberg -- Column: Designer's NotebookThe printed circuit board (PCB) is the primary base element for providing the interconnect platform for mounting and electrically joining electronic components. When assessing PCB design complexity, first consider the component area and board area ratio. If the surface area for the component interface is restricted, it may justify adopting multilayer or multilayer sequential buildup (SBU) PCB fabrication to enable a more efficient sub-surface circuit interconnect.
IDTechEx Report Unveils 3D Electronics Status and Opportunities
04/22/2024 | PRNewswire3D electronics is an emerging manufacturing approach that enables electronics to be integrated within or onto the surface of objects. 3D electronic manufacturing techniques empower new features, including mass customizability, greater integration, and improved sustainability in the electronics industry.
NASA, Japan Advance Space Cooperation, Sign Agreement for Lunar Rover
04/11/2024 | NASANASA Administrator Bill Nelson and Japan’s Minister of Education, Culture, Sports, Science and Technology (MEXT) Masahito Moriyama have signed an agreement to advance sustainable human exploration of the Moon.
Lockheed Martin Conducts Historic LRASM Flight Test
04/04/2024 | Lockheed MartinThe U.S. Navy in partnership with Lockheed Martin [NYSE: LMT] successfully conducted a historic Long-Range Anti-Ship Missile (LRASM) flight test with four missiles simultaneously in flight.