How to deal with the phenomenon of bubble formation and the treatment methods after lead-free solder paste?

Lead-free solder pasteHow to deal with the phenomenon of bubble formation and the treatment methods? When using lead-based solder paste, during operation, the bubbles inside the solder joints are places where heat is stored. The heat generated during the operation of the component will accumulate in the bubbles, thus making it impossible to smoothly extract the solder joint temperature through the solder pad. The longer the working time, the more heat is accumulated, and the greater the impact on the reliability of the solder joints. Therefore, there are still many small details in our daily work. As long as we pay attention to these matters in our work, we believe that we can avoid blisters.

When people use lead-free solder paste, many blistering situations often occur. Bubbles caused during welding not only endanger the reliability of the welding, but also the randomness of the location where the bubbles are caused increases the probability of electronic device failure. When electronic devices are in operation, the bubbles inside the soldering layer act as a heat storage area. The heat generated by the electronic devices during operation accumulates in the bubble formation, resulting in the soldering temperature not being able to achieve success and relying on the output of the soldering layer. The longer it operates, the more heat it accumulates, which will cause great harm to the stability of the welding.
The direct cause of welding transforming into bubbles:In order to adopt it betterSACWhen alloy products achieve the expected thixotropy and interconnection, compared with the flux in lead solder paste,SACThe flux in the solder paste must operate at a relatively high ambient temperature, andSACThe surface tension coefficient of alloy products exceeds that of tin-aluminum alloy. The probability of capturing volatile organic compounds in the molten welding materials has increased, and these volatile organic compounds cannot be removed from the molten welding materials, thus making it impossible to avoid the formation of bubbles. However, we can rely on various methods to eliminate the formation of bubbles. Since the common gas reflow soldering equipment cannot be converted into a vacuum inside the furnaceO2The bubbles inside the welding cannot be effectively and reasonably eliminated. In order to better prevent the hydrocarbons used in welding from posing a safety threat to the reflow soldering furnace, due toN2The working pressure is higher than the atmospheric pressure, and a large number of bubbles are formed inside the welding. Then, how to solve the situation caused by bubbles after using heavy metal-free solder paste?

1After welding, during the stage before cooling down, the vacuum pump should be pumped in a gradient direction, that is, the vacuum pump value should be gradually increased. Since the welding material is still in a liquid state after welding, bubbles will be scattered on every part of the weld at this time. The gradient direction mechanical pump can initially draw the bubbles away from the surface, and the bubbles at the bottom need to move upwards. As the burden decreases, the bubbles will be discharged evenly. If the gas is discharged immediately, the cracked loan opening will fall on the weld.

2Pre-pump to the vacuum pump. Before heating the lead-free solder paste properly, the operating range should be adjustedO2Draw it to the vacuum pump to prevent it from converting into an air oxide film during the heating stage. Vacuum will also enhance the lubricity range. Indeed, removing the above will cause bubbles to appear after the application of lead-free solder paste. There are also many small key points in everyone's work. As long as everyone pays attention to these situations at work, I firmly believe that blisters can be avoided.

Shenzhen CityJJYCarry out mutually beneficial cooperation with electronic raw material producers, and also produce solder wires, solder rods, solder pastes and flux pastes for other enterprises. With a rich variety of successful cases in the research and development of chemical raw materials, our overall strength has created a sales market that is of high quality and honest and trustworthy.