If the solder balls emerge from the tin-planting board during the blowing process, resulting in many points not being planted, use a blade (must be sharp) to flatten the protruding part of the tin-planting board. Then fill the unplanted holes with the solder paste, blow it again with an air gun, and when the solder paste melts, stop heating and you will find that the tin spot size is very uniform.
2022-10-09