Solder ball planarization method and substrate structure of ball grid array semiconductor package using solder ball as input / output terminals

摘要

The present invention relates to a solder ball planarization method and structure thereof of a ball grid array semiconductor package using solder balls as input / output terminals. To this end, in the present invention, the metal solder ball lands having different diameters are formed on the inner and outer portions of the substrate surface to which the solder balls are attached, and the solder mask is formed on the portion of the substrate surface where the lands are not formed. Solder balls of different heights are formed according to the diameter of the substrate, or a plurality of metallic lands having the same size are formed on the substrate, and then a solder mask is formed on the substrate. The land center portion is formed to cover the outer portion of the land, and the exposed portion of the land is formed in a different size at the center and the outer portion of the substrate, so that the solder balls of the same size are placed on the land, and then welded to the land diameter. Therefore, solder balls of different heights are formed. Accordingly, the relative height of the solder ball can be flattened.