T6, T7, T8, T9, and T10 solder powder are called ultra-fine solder powder because of their small particle sizes. Solder paste consisting of T6 to T10 solder powders is called ultra-fine solder paste. With the ongoing advancements in the microelectronics and semiconductor industry, there is a trend towards decreasing chip sizes and increasing packaging densities. Traditional solder paste products rated at T4 and above are increasingly inadequate for meeting the stringent requirements of microelectronics and semiconductor packaging. Consequently, there is a growing adoption of  ''ultra-micronized'' solder paste formulations in packaging applications.