1. Temperature of soldering iron

　　SMT tends to work at a temperature equivalent to that of a hot soldering iron (approximately 375 ℃), making things faster and requiring fine-grained IC welding techniques to work below. The actual temperature setting will vary for different irons, but it may range from 330 ° C/626 ° F to 380 ° C/716 ° F (although some inexpensive temperature controlled soldering irons may not have accurate temperature settings if they do not work well, so try to be higher). Most modern components have a considerable amount of elasticity and are designed to handle automatic welding and lead-free solder, but even at these high temperatures, it is best not to leave contact with the iron for too long,

　　2. Solder 0805 chip resistors and capacitors

　　Apply flux to both pads.

　　Use tweezers and/or tips to achieve the position of the component.

　　Load some solder onto the soldering iron head.

　　At the same time, use a tip to keep the component in place, and touch the soldering iron to one end of the component, so that the solder flows to the pad and component ends.

　　Then load some solder onto the soldering iron head and repeat with the other end of the component (which does not need to be held in place at this time).

　　The connection inspected with a magnifying glass is good, and there are no pads or components near the welding bridge for visual inspection.

　　3. Solder SOT-23 transistor

　　Apply flux to all three pads.

　　Use tweezers and/or tips to achieve the position of the component.

　　Load some solder onto the soldering iron head.

　　Simultaneously using a tip to maintain the component in place, touch the soldering iron to the middle pin/pad so that the solder flows to the pad and pin.

　　Then repeat this process for the other 2 pins (it will not require this time to hold in place).

　　The connection inspected with a magnifying glass is good, and there are no pads or components near the welding bridge for visual inspection.