The LED lamp bead copper wire process has been researched and developed by LED lamp manufacturers because of its cost reduction, and has been applied by many manufacturers. However, according to the feedback from customers relative to gold wire welding in practical applications, there are many problems in the copper wire process. Below we summarize these common problems, hoping to help everyone.

 1. The aluminum layer of the first solder joint is damaged, especially for the thickness of the aluminum layer <1um;

 2. The second solder joint defect is mainly due to the fact that the copper wire is not easy to combine with the bracket, resulting in cracking or damage of the crescent moon, resulting in poor second soldering and reliability risks during customer use;

 3. For many brackets, parameters such as the power of the second solder joint, USG (ultrasonic) friction and pressure need to be optimized, and the good rate is not easy to increase;

 4. The copper wire is oxidized, causing the deformation of the gold ball and affecting the product qualification rate. It is difficult to unpack during failure analysis;

 5. The training period of operators and technicians is relatively long, and the skills and quality of employees are required to be higher than those of gold wire welding, which will definitely affect the production capacity at the beginning;

 6. The MTBA (hourly output rate) of the equipment will be lower than that of the gold wire process, which will affect the production capacity;

 7. The cost of consumables increases, and the life of the cleaver for copper wire is usually reduced by half or more than that of gold wire. At the same time, it increases the complexity of production control and the cost of porcelain nozzle consumption;

 8. Material confusion is prone to occur. If there are gold wire and copper wire processes in production, the production control must pay attention to the storage life and distinguish the list of materials. Wrongly typed or oxidized wires can only be scrapped. Miss operation warnings often appear, and the risk of failure increases. Big;

 9. Compared with gold wire welding, in addition to the ignition rod (EFO), there are more forming gas (synthetic gas) protective gas delivery pipes, and the positions of the two must be aligned. This directly affects the yield. Precise control of the protective gas flow, the cost will increase with more use, and the defect rate will be high with less use;

 10. Al Splash. Usually easy to appear in wafers with thick aluminum layers. It is not easy to identify the impact, but be careful not to cause a short circuit. It is easy to crush the PAD or a solder ball. Cause low test results or customer complaints;

 11. Oxidation occurs after finishing the line, there is no standard judgment risk, it is easy to cause poor contact and increase the defective rate;

 12. It is necessary to re-optimize the Wire Pull, ball shear test standards and SPC control lines. The current gold wire usage standards may not be fully applicable to the copper wire process;

 13. There will be some restrictions on the underlying structure of the Pad at the first solder joint, such as Low-K die electric, those with vias, and those with circuits on the bottom layer, which require careful risk assessment. The existing wafer bonding Pad design rule for copper The line process needs to be further optimized. But today's packaging factories using copper wires do not seem to be enough to influence the development of chips;

  14. The copper wire process may have reliability problems for the use of non-green plastics (containing halogen elements). If there is fluorine or other impurities on the pad, the reliability of the copper wire will also be reduced.

  15. Assessments for things like Die to Die bonding and Reverse bonding are incomplete.