Optimization of Process Parameters for Pressure Welding of Shells by Ultrasonic Welding Machines

Optimization of process parameters for ultrasonic pressure welding of housings

Ultrasonic welding is also known as "bonding" is the use of ultrasonic frequency (16 ~ 120 kHz) of mechanical vibration energy, connecting the same or different metals, semiconductors, plastics and ceramics, etc., a special welding method. Ultrasonic welding is now widely used in integrated circuits, capacitors, ultra-high voltage transformer shielding components, micro-motors, electronic components and batteries, plastic parts such as packaging production. Compared with the traditional welding technology, ultrasonic welding technology with high speed, high efficiency and high automation and other advantages, to become a semiconductor package within the interconnection of the basic technology!

The basic principle of ultrasonic pressure welding

Ultrasonic energy is the vibration of mechanical energy, the working frequency exceeds the sound wave (normal human hearing, the upper limit of its frequency is 18 kHz). The frequency of ultrasonic pressure welding used for semiconductor packaging is typically 40 kHz to 120 kHz. ultrasonic pressure welding is a solid-phase welding method, and this particular solid-phase welding method can be briefly described as follows: At the start of welding, a strong plastic flow of the metal material occurs under friction, creating the conditions for contact between the pure metal surfaces. The temperature rise in the joint area, as well as the high-frequency vibrations, further create an activated state of the atoms on the metal lattice. As a result, when metal atoms with covalent Kin properties approach each other to a distance measured in nanometers. It is possible to form interatomic electronic bridges through the common electrons, i.e. to realize the so-called metal "bonding" process.

Studies of the welding process have shown that friction, plastic flow and temperature are the three main interdependent factors for ultrasonic welding, with friction playing a dominant role, not only as the main heat source in the welding, but also by removing the oxidized film to create the conditions for contact between pure metal surfaces.