A-1, and important of is is requirements Tin powder particles size distribution uniform, here to talked about Tin powder particles degrees distribution proportion of problem; in domestic of solder powder or solder cream production manufacturers, everyone often with distribution proportion to measure Tin powder of uniform degrees: to 25~45 μ m of Tin powder for cases, usually requirements 35 μ m around of particles points degrees proportion for 60% around, 35 μ m following and the above part the accounted for 20% around;
A-2, also called Tin powder particle shape is more rules under the "People's Republic of China electronic industry standard of the General specification for tin-lead solder paste (SJ/T 11186-1998)" provides as follows: "metal powder shape is spherical, but allow longer axis and minor axis of the largest ratio of 1.5 near-spherical shape powder. As the user agreement with the factory, but also for other shapes of alloy powders. "In practical work, Tin powder is usually required long and short axis ratio generally below 1.2.
A-3, if A-1 and A-2 's request does not meet the above basic requirements, in the use of solder paste, will likely affect the solder paste printing, point, welding results.