Plasma technology for surface treatment
bdtronic plasma surface treatment systems offer an up-to-date pre-treatment method for a durable adhesion. See here in detail how perfect the bdtronic Plasma VP4 technology works.
Atmospheric pressure plasma
Atmospheric plasma systems usually require only air and electricity to optimally prepare surfaces before adhesion processes. The plasma heads on these plasma surface treatment systems are space-saving and can be easily integrated into any automation solution, for example together with dispensing heads or in continuous production lines.
Low pressure plasma BPS-LP
Under the trademark BPS-LP we offer you inline-capable low pressure plasma surface treatment systems. Those devices can be integrated before a fully-automated vacuum dispensing process to improve the flow properties, adhesion as well as a long-term stable density. The available chamber volume on plasma adhesion systems is adjusted for typical work piece conveying systems.
Process control of plasma treatment systems
Our plasma surface treatment systems are equipped with tamper-proof control PCs to ensure process safety for your applications. The systems also provide continuous monitoring and control functions.
What is Plasma?
Plasma is a partially-ionised gas, in which the degree of ionisation fluctuates and may sometimes be very low. More than 99% of the universe surrounding us is in a plasma state. Examples of this include lightning, polar lights, sunlight or candlelight. As plasma is created by high energy input, it is considered the 4th state of matter and is typically in a gaseous state.
Technically, plasma is generated through the creation of an electric field which ignites a gas flowing through (e.g. air or other gases) to form plasma. Plasma is quasi-neutral, but as it consists of free charge carriers or highly-reactive particles, it is energy-rich and can trigger various physical and chemical reactions. This characteristic is used in industry to generate various effects.
ATMOSPHERIC-PRESSURE PLASMA AND LOW-PRESSURE PLASMA
Artificially-created plasma is used as a physical surface pre-treatment method. Alongside “hot” plasmas for plasma welding or plasma cutting, these technologies are considered “cold” plasmas. We make a distinction here between low-pressure plasma (LPP) and atmospheric-pressure plasma (APP). APP systems are typically devices which can be integrated into various automation solutions under normal pressure conditions, and where the plasma chamber is located in a head which can move along the section of a part to be processed. APP systems are ideal for integration into production lines for industrial applications, for example before applying adhesive beading or liquid seals.
LPP are chamber systems in which a vacuum is first created and then a process gas fed through, which then ignites to form plasma. In LPP systems, the components are placed or fed into a chamber. The plasma can reach and flush virtually the entire open surface of a product, including cavities, whilst APP systems are used on specific points and are limited with regard to their effective depth and width.
PLASMA TECHNOLOGY EFFECTIVENESS
When plasma strikes a surface, it breaks molecular and intermolecular bonds and creates chemical reactions, so that the treated surface has much higher surface energy and greater oxygen enrichment following a plasma process. The surface therefore allows much greater wettability (hydrophilic property) and adhesion (bonding). A change in the surface roughness can also be seen. In theory, the effects can be classified as fine or very fine cleaning, as activation or as functionalisation of a surface.
These effects enhance the adhesion of glues, print materials, plastics or other media, and therefore the durability of such joints even under greater loads. One example of this is a sensor fitted to the outside of a vehicle which is exposed to spray and corrosive saline solution in winter.
Cleaning normally has a penetration depth of nanometres to micrometres. As no surface is ever 100% clean, but has certain barrier layers of impurities, adsorbates and reaction layers (additives, oxides), very fine cleaning is required for further processing.
POTENTIAL USES FOR PLASMA TECHNOLOGY
Plasma technology is used in many industries and sectors: Automotive, electronics, packaging, renewable energy, consumer goods, etc. One main area of focus is safety electronics in the automotive industry.
Various goals, which can be achieved using plasma technology, are pursued.
- Removal of boundary or residual layers: As preparation for subsequent processes such as gluing, coating, etc. The surface is pre-treated with plasma technology so that the unwanted substances, adsorbates, and dust particles can be removed. Plasma technology allows materials to be processed further immediately after plasma cleaning.
- Increased surface tension: The surface of plastics, metals and other materials is changed by the use of plasma technology so that the surface tension is increased to the required level, which in turn significantly improves the wettability.
BENEFITS OF PLASMA TECHNOLOGY
Plasma technology is an important basis for developing innovative production processes and material combinations, as well as new products. Since this means that many new materials can be combined, this creates considerable material freedom which is of great importance to industry. This can also lower material costs. Plasma technology is sufficiently advanced to allow the plasma process to be combined with the following dispensing process. As a result, not only are durable and strong assemblies formed, but the processes are more reliable overall.
Plasma technology has the advantage that product surfaces have good surface cleanliness and wettability.
The machines and devices used for plasma technology are suitable for stand-alone workstations as well as fully-automated series production of products. Reliability is the primary issue here. The use of plasma technology as a pre-treatment method is of particular interest to high-volume production, i.e. production with quick output and a high degree of automation. Further to this, plasma process stands for excellent reproducibility, reliability and user-friendliness, as the process is free of volatile, harmful chemical components.
Plasma pre-treatment is a contactless process, i.e. the plasma is beamed at a defined distance from the component surface. This also allows the plasma technology to reliably clean complex modules, such as populated PCB boards, grooves or three-dimensional sections.
VP4 – VARIABLE PLASMA
VP4 plasma technology is suitable for very fine cleaning and activation before gluing, soldering, wire bonding, overmoulding, casting, printing or other processes which require a clean and polar surface for adhesion.
The VP4 technology provides for stable and repetitive processes through continuous monitoring of the relevant parameters. The plasma system can be integrated into production solutions, whether lean production, fully-automated line assembly or robotic handling.
The transformer in the VP4 system is integrated into the plasma head. Therefore it works without a high-voltage cable. The system can be connected to a standard cable, and is therefore very easy to integrate. As there are no power losses due to a high-voltage cable, the system is highly energy-efficient.
VP4 plasma technology allows a dynamic, continuous and variable performance adjustment including gas flow regulation. The system is suitable for applications on plastics as well as metals. To allow the plasma processing in combination with a dispensing process, the air flow rate, the power, and the limits can be automatically adjusted..
RELIABILITY THROUGH PROCESS CONTROL
Perfect results in use are guaranteed by continuous process control. Tools for this may include tamper-proof control PCs, which constantly monitor the systems. The process control monitoring function makes a huge contribution to reliability. Parameters monitored include gas flow, gas pressure, flow rate control, power, ignition, operating voltage, hour counters and wear.