Electrodes for one-sided contact and impulse welding
 Electrodes are intended for welding wire and ribbon leads when assembling semiconductor devices, big and hybrid-type intergraded circuit on plants with independent (electrodes of EI1, EK2, EK4 types) and parallel (electrodes of EI2, EK2, EK3, EK5 types) travel of wire and an instrument. Diameter of welded wire makes from 0.020 up to 0.100 mm, and size of the welded ribbon – 0.15*0.8 mm.
Depending on the type of welding the electrodes are manufactured of two types:
1. Electrodes for one-sided contact ultrasonic welding: EK1, EK2, EK3, EK4, EK5.
2. Electrodes for one-sided impulse ultrasonic welding: EI1, EI2.
The electrodes of EK type consist of two current-carrying elements separated with insulating plate mica or sputtered film and inflexibly fixed together by means of
dielectric bush.
Electrodes of EI type are made in the form of V-shaped plate having an area of increased resistance in the working part; area in operating mode is heated with an impulse of electric current.
During welding at the moment of press of the welded wire or ribbon with an electrode, current is transmitted through the working elements of electrodes.
When current passes through the contacts of the bonded parts, at the point of contact thermal energy is emitted.
External pressure in combination with heating contributes to formation of a fast weald seal. Type of weld seal performed with electrodes – “overlapped”.
Material for production of electrodes of EK-type: hard metal, and of those of EI-type: nichrome.
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