Improvements, issues and highlights of lead-free solder paste in SMT processes

SMTUsed in the processLead-free solder pasteImprovements, issues and highlights: Generally speaking, solder joints with lead solder paste are brighter,Because it contains lead components.Lead-free solder paste solder joints are darker,Because there is no lead component in it.Solder joints are not necessarily better the brighter they are,The weld points are required to be smooth and glossy.PCBASpecial cleaning agents should be used when cleaning,Remember not to clean with alcohol. The most important factor is that when soldering solder paste with the same composition, the soldering temperature, that is, the reflow soldering temperature, must be adjusted. These elements play a crucial role. JJY Soldering Factory can provide free sample testing according to your requirements and offer strong technical support to ensure a smooth operation process for you. Next, the editor will introduce several highlights and methods to you all:

　1. Select solder paste with good antioxidant properties and high silver content

　　Lead-free solder paste placed in the air is prone to volatilization and oxidation, which reduces the performance of the solder paste. At this time, the brightness of the solder paste solder joints is not as good. Therefore, solder paste with better oxidation resistance should be selected, and at the same time, it should be avoided to be placed in the air for more than a certain period24Lead-free solder paste for a few hours. Choosing lead-free solder paste with a relatively high silver content can increase the brightness of the solder paste solder joints at the same time. However, increasing the silver content will raise the cost, which depends on the affordability of each manufacturer.

　　Second, improve the reflow soldering process

　　Firstly, when reflow soldering, adding nitrogen can increase the brightness of the solder joints of lead-free solder paste. There is another reason for the insufficient brightness of the solder joints, which is the residue of flux. At this time, the temperature curve of the reflow soldering can be adjusted, and the constant temperature zone time of the reflow soldering can be appropriately increased to enable the flux to evaporate to a greater extent, which is conducive to the brightening of the solder joints.

Shenzhen JJY Industrial Technology Co., Ltd. was established in2008years10Moon It is a provider of customized solder solutions integrating the research and development, production customization and solution services of electronic solder (solder paste, solder wire, solder bar, etc.). The brand "JJY" operated has been selected for the Brand Power Demonstration Project [Soldering Materials].

　　Iii. Select the flux correctly

　　Sometimes, there may be yellow substances remaining on the solder joints, which is due to the residue of flux. Therefore, to enhance the brightness of the solder joints, it is also necessary to select the flux correctly. Using a no-clean flux can be of certain help to the brightness of the solder joints.

　　Want to use it againLead-free solder pasteAt this time, the solder joints become brighter. A very effective method is to increase the silver content, but the cost will naturally increase, which often deters many people. Therefore, a more effective approach is to improve the reflow soldering process and select good solder paste and flux. Hope it can be of help to you.