Other than meeting the Apple cosmetic criteria (080-01309 / 080-01261) or IPCA-610, Preferred solder go on top of the B2B terminals, in order to provideindication for a good solder joint under the 3D AOI inspection. In case of it is not,capable machine must be in place to make sure the solder joint issues, likedewetting, or insufficient solder at the side can still be caught.