An Electro-Magnetic Actuator for Printing Solder

A new actuator for printing a wide variety of fluids is presented. Fluids with a density up to 10 g/cm(3) and a surface tension up to 550 mPa can be printed. The printhead works up to 500 degrees C. Several application areas, such as printing of solder, and 3D-printing for the presented printhead are possible. With this actuator measurements with water are accomplished. The droplet volume and velocity in dependence of the control signal are measured. Droplet volumes in the range from 500 to 2500 pl and droplet velocities from 2 to 7.5 m/s are obtained. Further measurements approve the printing of solder. A test layout for the placement of flip-chips is printed and the diameter and the height of the bumps are measured. The standard deviation is calculated in order to approve the repeatability of the process.