What are you looking for?
Copper is a typical optional material, which can be connected to conductive parts through micro welding because of its excellent ability to effectively conduct electric energy and transmit signals. However, as an excellent choice of conductor, copper has extremely high heat conduction performance, which will quickly diffuse heat from the welded joint, making it difficult to maintain heat balance and conduct reliable welding. The trend in the industry is to increase the production speed, reduce the size of parts and weld the cross-sectional area of dissimilar materials and dissimilar conductors, which makes the characteristics of rapid heat conduction of copper become a difficult problem in micro welding. 532 nm or green wavelengths can control the heat balance of these small and highly conductive components while ensuring that they are not overheated or underheated.
Micro welding can be accomplished in several ways: ultrasonic welding, resistance welding and laser welding. Each kind of welding has its advantages and disadvantages. Each kind of welding can meet the requirements of micro welding to some extent.
It is very suitable for plate welding, but it will reduce the production speed. Ultrasonic welding uses vibration energy to weld on the connection interface. The vibration energy transmitted to the interface is provided by the ultrasonic generator or welding head contacting the top part. The welding head vibrates at a frequency of hundreds of times per second, with a motion amplitude between 0.0005 and 0.004 inch. The lower side of the component is supported by a bottom anvil, which can be static or vibrating. The vibration under the applied force causes the plastic deformation of the uneven surface on the welding interface, resulting in the formation of highly close contact and metal atom diffusion. The connection is formed by diffusion and there is no melting at the connection. The component has some deformation or thinning, but it can be controlled normally. The contact between the welding head and components is maintained through the friction of the welding head, and the friction is strengthened through the embossing pattern on the welding head. Ultrasonic welding is particularly suitable for sheet welding of conductive parts, including aluminum and copper. Ultrasonic technology has some disadvantages in micro welding. Mechanical contact is required on both sides of the connection due to the need to transmit force to the component. In addition, the welding head is a consumable that requires inspection and replacement. The geometry of the connection is limited to lap welding to some extent. Finally, affected by the welding head drive, the welding cycle speed will reduce the production speed.
The resistance welding process is flexible, but it is not suitable for mechanical precision parts. Resistance welding uses the high resistance of the welding interface to generate heat when current passes through the component. The current is generated from the same side or the opposite side of the workpiece, which contacts the electrode of the component to form a circuit. Apply some force to the components to ensure electrical contact. When welding conductive parts by resistance welding, the electrode has resistance, so it performs two functions: heating and transferring heat to the parts, and conducting sufficient current to generate some heat at the connection interface. Resistance welding is suitable for a wide range of connection applications and materials with excellent performance. However, since the process of resistance welding depends on mechanical contact and the need to form an electrical circuit between two electrodes, it can not be operated in all cases, especially when the parts are mechanical precision parts. In addition, the diameter of the smallest electrode is about 0.04 inch, which will limit the access operation of the connection.
