SMT SOLDER PASTEPRINTING MACHINE-CONSTANT TEMPERATURE AND HUMIDITY MACHINE ECU

1. The Effect of Temperature on Solder Paste: Experiments show that the viscosity of solder paste decreases with increasing temperature.

2. Lower viscosity causes the following problems:
A. Reduced viscosity leads to bridging and diffusion, causing the solder paste to spread laterally during printing; B. Reduced viscosity causes collapse, resulting in insufficient holding force and bridging of the printed solder paste blocks. This phenomenon usually occurs after the printing process (like a mudslide);
C. Reduced viscosity causes defects, poor demolding, blocked holes, and poor molding. Therefore, temperature has a significant impact on the viscosity of wet solder paste, directly affecting the core quality of the product. Controlling the internal operating temperature of the printing press during the printing process is crucial.

3. The Effect of Humidity on Solder Paste Viscosity: Humidity is a physical quantity representing the degree of dryness of the atmosphere. At a given temperature, the less water vapor in a given volume of air, the drier the air; the more water vapor, the more humid the air. The degree of dryness or humidity of the air is called “humidity.” Experiments show that when humidity is too low and the weather is dry, solder paste dries out easily, which is particularly noticeable in northern winters. Below 40% relative humidity, the viscosity of solder paste decreases as humidity decreases. Above 60%, excessive moisture in the air causes water droplets to crystallize on the surface of the solder paste, severely impacting its quality.

In conclusion, the use of temperature and humidity control systems has become crucial in SMT printing. After installing a temperature and humidity control system on an SMT printer, the viscosity of the solder paste increases more slowly during printing, significantly reducing via blockage, eliminating buildup, stringing, and edge defects, resulting in a comprehensive improvement in print quality. It ensures that air temperature and humidity are strictly controlled within the set parameters, 24 hours a day, 365 days a year, providing a good operating environment for the SMT printer and guaranteeing SMT print quality with effective and reliable conditions.

An environment control unit (ECU) is a device that uses compression refrigeration and humidification to maintain the ambient temperature to our desired level.

Our company designs and manufactures environment control equipment for solder paste printers, aiming to provide optimal operating conditions and comprehensively improve printing quality during the SMT manufacturing process.