Capacitor assembly machines are used to manufacture capacitors, passive electronic components that store energy in the form of an electrostatic field. In their simplest form, capacitors consist of two conducting plates separated by an insulating material called the dielectric. Capacitor assembly machines may be designed for specific types of plates and dielectrics, and differ in terms of product and performance specifications. Capacitor making machines are often categorized according to capacitor type. Choices include capacitor assembly machines for aluminum electrolytic capacitors, ceramic capacitors, chip capacitors, film capacitors, high voltage capacitors, tantalum capacitors, power capacitors, and ultracapacitors. Capacitor winding machines are also available.
Capacitor assembly machines are designed for slow-speed pilot lines, medium-speed assembly lines, or high-speed assembly lines. Product specifications include parts per minute and parameters such as power supply. The number of stations is also important to consider. Automatic capacitor assembly machines are designed to manufacture capacitors without operator assistance. By contrast, semi-automatic systems require some operator involvement. Both types of devices may have analog or digital control panel. Analog controls for capacitor assembly machines include dials, switches, and knobs. Digital control panels provide numeric, graphical, or even touch screen displays. In terms of applications, capacitor assembly machines may be designed specifically for the aerospace, automotive, consumer electronics, and medical device industries.
Film capacitor assembly machines are designed to roll plastic film or paper and film with aluminum or copper foil. Because plastic films contain small imperfections, capacitors are made with multiple layers of thin films rather than a single layer of a thicker film. Multi-layer designs are essential for high-voltage applications, where as many as seven layers may be required. There are two main methods for capacitor winding: insert tab and extended foil. Insert tab equipment puts a small metal tab into the winding at a specific number of turns. The foils are separated by a physically wider film and wound over each other. Extended foil equipment also winds the foils, but so that they are offset. Film capacitor assembly machines of this type also solder the ends, providing lower self-inductance and enabling the capacitor to discharge larger peak currents.