The Causes and Solutions of lead-free Solder Paste Bubbles - JJY Solder Paste Manufacturer

Lead-free solder pasteWhat are the causes and solutions of bubbles? Many people are asking why some bubbles appear from time to time when using solder paste and whether there is any impact. Now let me tell you all that if bubbles appear, it not only endangers the stability of the solder joints but also further increases the probability of component failure,The vast majority of electronic component manufacturers will apply lead-free solder paste. When using lead-free solder paste for production and processing soldering, how to avoid it or what solutions are there? The following is an explanation from JJY solder Paste manufacturer:

These problems often occur frequently because when lead-free solder paste is used for soldering work, the bubbles inside the solder joints act as a specific heat source and are the areas where heat is stored. The heat energy generated during the actual operation of the component will be deposited in the bubbles, thereby causing The temperature of the solder joint cannot be stably drawn out according to the solder layer. The longer the working time, the greater the heat deposited, and the greater the harm to the stability of the solder joint.
        Lead-free solder paste, in order to better penetrate the expected moisture and achieve the final connection within its service life, must function at a higher temperature compared to the solder paste in leaded solder paste. The working temperature of the solder paste is higher, and the interfacial tension is also greater than that of tin alloy, increasing the probability of volatile organic compounds trapping in the molten solder material. This volatile organic compound cannot be carelessly discharged from the molten welding material, and thus the formation of bubbles is inevitable. However, we can use some reasonable and effective methods to remove the bubbles.
        Because the general vacuum pump flowing back to the machine equipment cannot create a vacuum, it cannot properly remove the air inside the furnaceO2And the bubbles within the solder joints. In order to avoid it better Air oxidation of the solder jointN2Maintain the reflux furnace due toN2When the working pressure is higher than the atmospheric pressure, a large number of internal bubbles are caused instead. So, how can we eliminate the bubbles caused during lead-free soldering? In order to avoid the protection of the reflow soldering furnace by nitrogen oxides during soldering, given that the pressure of nitrogen is greater than the atmospheric pressure, a large number of bubbles are generated inside the soldering process. Then, how to solve the problem of bubble formation after using lead-free solder paste?

1After welding, during the process before cooling, perform a gradient vacuum pumping, that is, gradually increase the vacuum value. Given that the solder is still in a liquid state after welding, bubbles are scattered throughout each part of the weld at this time. The gradient vacuum pump can first remove the bubbles from the surface layer, and the bubbles below will move upwards. As the pressure drops, the bubbles will flow out evenly. If the air is expelled immediately, the crack will land on the weld.

2Pre-evacuate to a vacuum, then correctLead-free solder pasteBefore heating is completed, the oxygen in the operating range should be evacuated to a vacuum to prevent the formation of an oxide film during the heating process. A vacuum environment will also enhance the wettability range. Indeed, apart from the above-mentioned phenomena that may cause lead-free solder paste to bubble after use, there are also many small details in everyone's work. As long as everyone pays attention to these phenomena at work, I believe that bubbling can be completely eliminated. 

  Everyone can also pre-vacuum package. Before heating the lead-free solder paste, first put it in the working areaO2Drain completely to prevent the formation of an air oxide film during the heating process. Welding under vacuum can also increase the total wet area. Therefore, we still need to be careful during the usage process and not be too hasty, which may cause unnecessary problems. If you have any questions, you can consult JJY Solder Paste Factory, which will answer some of your questions. Welcome to consult!