I'm working in Solder paste manufacturing industry and my customer has complained the void issue on BGA pad. I'm internally conducting the void test on BGA pad in my Lab. I used OSP furnish board with Sn/Pb and /or lead free component using Lead free solder paste.
And I have also tried many different profiles to see whether void can be improved by profile. However, we do not see much different using this test method under X ray observation.
I could not see any different in a void when I put component while perform test and I only see slight different in void when I conduct test without putting component.
However, I still could not differentiate the void level between good and bad paste using above test method.
I would like to know how usually solder paste manufacturer use to conduct the void test in their lab.
What kind of test board furnishes and/or component to use when perform void test under X-ray? What kind of component furnish and size do we need to choice?
Anybody has any idea how to perform the void test in Lab? Appreciate your advice??