Overview

Certain factors such as ambient temperature changes and different material lots can cause viscosity fluctuations. These fluctuations affect the performance and consistency of coatings that are applied to printed circuit board assemblies. By controlling the temperature of the conformal coating fluid circuit, viscosity fluctuations can be reduced.

The Viscosity Control System ensures a consistent fan pattern – even after idle – through the unique design that circulates heated fluid through the applicator maintaining a consistent nozzle temperature at all times. Programmers define the process temperature and the corresponding process limits in EasyCoat^® software. If the fluid temperature moves outside the defined process limits during production, the system triggers an alarm condition and operators can intervene to prevent potential errors.

Heat thins the coating material which can lead to reduced solvent usage. As a result, higher film builds can be achieved in a single pass because there are more solids in the coating material. Use of solvents can be reduced up to 15% while achieving the same coating results as a non-heated system. For more advanced process control, the Viscosity Control system can be combined with Nordson ASYMTEK's Laser Fan Width Control option that automatically verifies the fluid fan width. This combination allows users to perform process checks on the spot and as part of pre-programmed, regular equipment operation. Parameter settings are automatically adjusted quickly and efficiently without operator intervention.

The Viscosity Control system is an option on the Select Coat^®SL-940 conformal coating system with the Select Coat^® SC-104/105 or the Select Coat^® SC-280C applicators. 

Features

• Provides process control for conformal coating to ensure consistent coverage
• Eliminates viscosity changes due to ambient temperature fluctuations
• Keeps fluid at a constant temperature, within 1 degree C
• Protects material with an over-temperature alarm
• Includes a heated recirculating fluid circuit to eliminate viscosity changes in temperature-responsive materials
• Emissions of Volatile Organic Compounds (VOCs) may be reduced – up to 15% – depending on the fluid properties