Under the condition of meeting the function and performance of the product, the components should be packaged with surface mount type, wide spacing and low packaging complexity, so as to reduce the production difficulty and improve the production efficiency. Try to select the surface mount device, only do one reflow soldering, to complete the welding, do not need to carry out wave soldering. If it is inevitable to choose plug-in devices, we need to consider whether the reflow soldering process can be used to complete the welding and reduce the welding process and cost.