Conformal Coating Selection Guide
Conformal Coating Selection Guide
With conformal coating, there is always more than one way to meet the application requirements, and the user’s expertise can vary greatly. Here are some guidelines to step you through the initial applicator selection process. There are four primary choices for conformal coating applicators for the Select Coat® SL-940 and Select Coat® SL-1040 conformal coating systems, which are the Select Coat® SC-280 non-atomized film coater, the Select Coat® Applicator Series with the SC-300 Multi-Mode applicator with three modes of operation (bead, monofilament, and swirl) and the SC-350 Select Spray atomized high-velocity coater, and the SC-400 and SC-450 PreciseCoat® conformal coating jets.
ASYMTEK Select Coat SC-280: High-Speed Coating with Excellent Edge Definition
The key benefits of the Select Coat SC-280 film coater are the high speed and excellent edge definition for selectively applying conformal coating materials with viscosities less than 100 centipoise. Coatings can be applied at line speeds up to ~750 mm/sec with single-pass coverage. Even at this high speed, the edge definition remains sharp, which allows for greater control in avoiding keep-out zones than is generally possible with an atomized spray process.
Furthermore, the availability of optional process controls such as VCS (Viscosity Control System), LFWC (Laser Fan Width Control), and Flow Monitoring makes the SC-280 film coaters the most suitable choice for high-volume manufacturing environments. The SC-280 film coater works best with solvent-based and low-viscosity 100-percent solid materials. The stainless-steel fluid path provides compatibility with all commercially available coating materials. Cured coating thicknesses generally range from 10 to 75 µm (0.0005 - 0.003 inch) for solvent-based materials and 100 to 200 µm (0.004 to 0.008 inch) for 100-percent solid materials.
ASYMTEK Select Coat Applicator Series
With its selection of multi-angled fluid extensions, nozzle sizes, nozzle types (low cavity and zero cavity), and four-position tilt capability, the Select Coat Applicator Series, including the SC-300 Multi-Mode and SC-350 Select Spray applicators, can handle the broadest range of applications, fluid chemistries, and viscosities compared to other Nordson ASYMTEK applicators.
SC-300 Multi-Mode: Three Modes of Operation for Flexible Adaptability
The primary benefits of the SC-300 are flexibility and adaptability. It is the only applicator capable of multiple pattern types (bead, monofilament, and swirl) within a single applicator. The monofilament is a non-atomized pattern, ideal for dispensing broad pattern widths while maintaining a good edge definition for high-viscosity materials. The swirl mode is a coarse spray, providing the benefits of atomized spray for less sensitive applications. The SC-300 can accommodate many fluid chemistries, such as silicones, acrylics, polyurethanes, and the newly emerging fluoropolymer hydrophobic coatings. The SC-300 is also fully compatible with solvent-based and 100% solid materials.
SC-350 Select Spray: Atomize High-Viscosity Coating Fluids with Excellent Edge Definition
The SC-350 Select Spray applicator is an optimized, single-mode spray coater that provides excellent edge definition and uniform coverage with the coating capability at top industry speeds. Improved air-assist efficiency allows for tight edge tolerance with increased selectivity and control near keep-out zones for a wide range of materials varying in viscosity from 30 to 3500 mPa-sec (30 to 3500 centipoise). It efficiently sprays solvent-based fluids while reducing solvent usage and the “cobwebbing effect” that occurs when coating fluids cure in-air. Ultimately, the SC-350 Select Spray applicator offers reliable processes at the low and high end of the viscosity spectrum for selective applications.
ASYMTEK SC-400 PreciseCoat Jet: Precision and Volumetric Control
The SC-400 PreciseCoat Jet offers precision and volumetric control. This applicator uses a standard dispensing needle to enable access around tall components. However, unlike standard needle valves that apply a continuous material flow, the SC-400 is designed for jetting discreet dots. The jetting action reduces satellites and accelerates the material just enough to break off from the needle tip cleanly. The dots can be spaced far apart to reduce the amount of material deposited and close together to provide good coverage. This method precisely regulates the total volume of material, allowing excellent control of dispensed lines. You can also use parallel lines to coat small areas. The SC-400 jet is compatible with low-viscosity materials, typically less than 400 centipoises. When using solvent-based materials, film thicknesses of 15 micrometers can be achieved, depending on the material.
ASYMTEK SC-450 PreciseCoat Jet: More Options with a Wider Viscosity Range
The SC-450 PreciseCoat Jet widens the viscosity range to provide more process options. It's ideal for coating with medium-viscosity silicones and urethanes from 125-1200 cps.
The PreciseCoat jet delivers dots and narrow line widths to 1.5 mm with improved flow control that eliminates masking. Designed for precise small-volume coating on substrates densely packed with components of varied heights requiring tight keep-out zone adherence and limited access near tall parts. The jet reaches locations not accessible by other applicators by using a needle design with jetting action and fast pulse-width modulated control. With greater accuracy, more process options, better usability, and a bubble-reducing valve design, the SC-450 is your solution for boosting precision, yield, and uptime.
The SC-450 pairs well with the ASYMTEK Select Coat® Applicator Series in dual-simultaneous and triple-valve configurations. It offers highly selective, small-volume coating accuracy near the tightest keep-out zones with dots and narrow line widths down to 1.5 mm. Repeatable fluid placement, coverage uniformity, and thickness make it ideal for coating individual parts and entire boards.