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www.us-tech.com


June 2025


The Power of the Plasma Pen: Revolutionizing Adhesion in Manufacturing


By Jeff Elliott P


lasma is a state of matter, like a solid, liquid, or gas. When sufficient energy is applied to a gas, it becomes ionized,


transitioning into the plasma state. With precise application and control, plasma can alter surface properties of a metal or plastic part without compromising the underlying mate- rial.


Although plasma has a wide


range of applications, it is frequently used to improve the adhesion of chemical glues, printing inks, and coatings. This is often the best solu- tion for manufacturers facing per- sistent challenges such as high fail- ure rates caused by delamination, inadequate bonding, poor surface printing, or issues with coating adhesion. “Plasma contains ions, elec-


trons, neutral particles, and reactive species that can be utilized for preci- sion cleaning, decontamination, increasing surface “wettability,” and other surface mod- ifications. These techniques can boost the bond strength by up to 50 times in certain cases,” says Ryan Blaik, sales manager of Corona-based PVA TePla. While there are multiple methods for


applying plasma to a product’s surface, one of the most popular and accessible are plasma “pens.” These tools ionize gas, such as air or noble gases, under normal (atmospheric) pressure conditions using electrical dis- charges. “The plasma produced from the tip of the


pen can be applied to very specific areas, or the entire part,” explains Blaik, adding that often plasma pens are incorporated into automated inline manufacturing processes or controlled by robots. According to Blaik, plasma pens serve as an affordable introduction to plasma technol-


ogy. Unlike traditional vacuum-based plas- ma chambers where parts are processed in high volume batches, the plasma pen can be


able, their surface is typically modified to become hydrophilic [attract water],” explains Blaik. “The plasma pen excels at making raw materials hydrophilic, enhancing their ability to bond effectively with chemical adhesives.” The plasma pen is particularly


effective for preparing materials in overmolding processes, including polypropylene applications, dip coat- ings, or any method that involves encasing or encapsulating compo- nents.


“The key aspect is enhancing


Plasma pens can be incorporated into automated inline manufacturing processes.


installed inline and costs less, requires less energy, and incurs lower operational costs.


Adhesion Challenges For most applications, plasma treat-


ments are utilized to increase the surface free energy of the material. Surface energy is defined as the sum of all intermolecular forces that are on the surface of a material, the degree of attraction or repulsion force a material surface exerts on another material. When a substrate has high surface ener-


gy, adhesives and other liquids often spread more easily across the surface. There are sev- eral mechanisms for increasing surface ener- gy with plasma, including precision cleaning, chemically or physically modifying the sur- face, increasing surface area by roughening, and by applying primer coatings. “Most materials are initially hydropho- bic [they repel water]. To make them bond-


the surface’s wettability,” says Blaik. “This allows the overmold to spread more effectively across the surface and minimizes the formation of bubbles or air gaps caused by low- energy surfaces. The result is a stronger and more reliable bond.” A common application of silicone overmolding is to safeguard electron-


ic boards against exposure to outdoor weath- er conditions. Without proper adhesion, sili- cone can begin to delaminate, not only at the edges of the PCB but also in the form of small air pockets on, or around, components. This can lead to moisture ingress and subsequent corrosion or electrical shorts. Another challenge is the topography of a


PCB, which means silicone must bond to many types of materials, including polymers, metals, alloys, ceramics and the FR-4 board itself, all of which have unique surface ener- gies and chemistries. PVA TePla developed a specific process


starting with a precision cleaning/surface activation treatment followed by the deposi- tion of an inert chemical primer that serves as a tie layer for the overmolding and pro- vides a uniform surface energy for the sili- cone to bond.


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