Which application is required?
At the beginning of a project, the task is defined in detail. Whether the task is to seal, encapsulate, fill, insulate or dissipate heat has a major influence on the choice of adhesive or encapsulation material and therefore on the subsequent process technology. If required, different tasks can be combined in one system. However, four main influencing factors must always be taken into account in this context: Homogeneity, air bubbles, moisture and the processing time of the materials used.
Filling is a potting method, in which low-viscosity materials are dispensed into a predetermined form. This technique is usually applied when sensitive electronic compounds have to be shielded from corrosive, chemical or mechanical influences. With regard to the geometry of a part and in accordance with the properties of the potting material in use, the filling application needs to be adapted individually for different component designs.
Sealing describes the application of highly viscous materials to a workpiece in the form of a bead. This process is usually carried out automatically along a specific, previously defined sealing contour. The main goal of this method is to protect sensitive components or electronics from dust, moisture, aggressive substances or temperature-related effects. During industrial production, such liquid seals are often applied as FIPG (formed in place gasket). In these cases, the workpieces are joined with the not yet cured liquid seal and then processed further. In contrast, the CIPG process (cured in place gasket) only allows further processing after the sealant bead has cured.
Increasingly smaller electronic devices with more and more functions within the smallest of spaces lead to ever higher heat generation and less surface area to dissipate it. In order to avoid a decline in performance or any defects in these electronic parts, the generated heat has to be dissipated reliably. This is achieved by using heat-conducting potting materials, also known as gap fillers. Due to their high performance requirements, these materials are highly viscous, highly filled and consequently highly abrasive.
Insulation describes the complete encapsulation of highly stressed electronic parts like transformers or ignition coils with appropriate potting materials. Apart from protecting coils from harmful environmental influences or other contaminations, further benefits of this method also improve the functionality and the properties of these parts. In order to avoid the inclusion of air bubbles, encapsulation under vacuum is the process of choice.
Adhesive bonding is the process of joining two or more parts with an adhesive. Since the adhesive dots or beads must be applied to a defined position, highly viscous dispensing materials are used which do not flow. However, depending on the application and the bonding properties to be achieved, low-viscosity adhesives may also be the materials of choice.
Coating describes the sealing of sensitive electronic surfaces by applying a thin layer of potting material or protective varnish. With regard to application and requirements, the layer thicknesses may vary from several micrometers up to a few millimeters. The aim is to protect sensitive electronics from environmental influences. However, in order to create a fully protective layer, a consistent coating of the surface area including sharp edges, soldered joints and other superficial structures must be ensured. Due to their self-leveling properties, mostly low-viscosity materials are used for this method.