In the PCBA processing process, laymen may think that the solder pastes are all the same, but in fact, the solder pastes used are different for different processed products. So, how to choose the right solder paste in different PCBA processing processes? Let's take a look at the following Sanjing.

The composition and purity of solder paste alloy powder are also different, oxygen content, particle shape, size, etc., will have a great impact on welding. Especially in the welding process, these factors may play a decisive role in welding quality. Therefore, when choosing solder paste, you need to pay attention to the following points:

(1) Choose the activity of solder paste according to the storage time of PCB and components: PCBA and components at different times have different performance in terms of solder paste activity. Generally speaking, RMA grades are used. Products with high reliability, such as aerospace and military products, should choose R grades. These have higher performance requirements, so you should choose a better solder paste during the soldering process. If the PCB and components have been stored for a long time, and the surface has serious oxidation, it is recommended to use RA grade solder paste, and it must be cleaned after soldering, otherwise the circuit board may not be used normally.

(2) Choose according to the assembly process and specific conditions of PCB products: Under normal circumstances, the solder paste selection for lead-plated tin printed boards is 63Sn/37Pb, and those containing palladium need to use 62Sn/36Pb/2Ag, lead-free process Sn-Ag-Cu alloy solder is selected for the other, the immersion gold board does not need to use silver-containing solder paste.

(3) Choose according to the value and purpose of the PCBA circuit board: If it is a demand for cheap electronic products, you don't need to pay much attention to the selection of solder paste. On the contrary, if it is a high-value, versatile PCBA circuit board product, it is necessary to choose high-quality solder paste. Even if the cost of solder paste will increase correspondingly, the chip processing plant will first consult the customer's opinion when quoting, and let the customer choose by themselves.

(4) Choose whether to use no-clean solder paste according to the cleanliness of the product: The no-clean process is more advanced than other processes, but not all soldering processes are suitable, so pay attention to selectivity when choosing.

The above is about the precautions when choosing solder paste for PCBA processing, I hope it can be helpful to everyone!