Memory and layout method of memory ball pads

A layout method of memory ball pads, used in a memory, the memory comprising a substrate and a plurality of memory ball pads, the memory ball pads disposed around the substrate so as to form a ring pattern which shows a bilateral symmetry by reflection, the layout method of memory ball pads comprising:

• dividing the plurality of memory ball pads of left-half part of the ring pattern into a first main area, a second main area, a third main area and a fourth main area wherein the first main area and the third main area have the same ball layout and the second main area and the fourth main area have the same ball layout;
• dividing the memory ball pads within the first main area into a first sub-region, a second sub-region and a third sub-region;
• disposing a plurality of input/output data pins and electricity power pins in the first sub-region and the third sub-region;
• and
• the plurality of input/output data pins are not adjacent to each other and at least one power voltage pin and at least one ground voltage pin are disposed next to each of the plurality of input/output data pins so as to optimize impedances of adjacent signals and reduce noise interferences.