This distance is not the smallest. It is no problem if you use an automatic welding machine, but manual welding does require some skills. First, hot air gun welding, the heat must be appropriate, otherwise you will lose the chip. The second is to use a soldering iron. First use the pull soldering method to apply tin to the entire row of pins of the chip at one time. In this way, the pins may be filled with solder, and finally you have to use the soldering iron to attract it, which may take several times. Only by sorting can you get satisfactory results.