摘要 |
An improved method for the attachment of lead electrodes to metallized film capacitors is disclosed herein. Capacitors of this type are formed by winding thermoplastic dielectric films, each having a conductive coating, into a coil and applying conductive electrodes to the opposite axial ends of the coil, forming an electrical bond with the metallized surfaces of the dielectric windings. The invented method provides for a two part heat curing of the capacitor. After the capacitor is wound into a coil, it is clamped and then heated at a moderate temperature below its rated operating temperature for a sufficient period of time so as to impart mechanical stability to the device. A "schooping" material is then sprayed on the axial ends of the capacitor, allowing for the deep penetration of the material between offset layers of the capacitor. Finally the capacitor is heated at a temperature above its rated operating temperature for a period of time sufficient to cause the dielectric films to contract into a tightly wound coil. The leads for the capacitor are then soldered onto the coil. The two part heat cure prevents the curling of the edges of the capacitor before the schooping process, allowing for greater penetration of the schooping material. This increase in penetration of the schooping material allows the capacitor to be used in applications requiring a higher current density then is possible by prior art methods. |